Step-by-step Solution:

1. Identify the reactants:

   • Galena is the natural mineral form of lead(II) sulfide, with the chemical formula $\mathrm{PbS}$.
   • The other reactant is nitric acid, $\mathrm{HNO}_{3}$.

2. Determine the chemical reaction and products: The reaction between a metal sulfide and nitric acid is a redox reaction. The products depend on the concentration of the nitric acid used.

   • Case 1: Reaction with dilute $\mathrm{HNO}_{3}$ When lead(II) sulfide reacts with dilute nitric acid, the sulfide ion ($S^{2-}$) is oxidized to elemental sulfur (S), and the nitrate ion ($\mathrm{NO}_{3}^{-}$) is reduced to nitric oxide (NO). The lead ion forms lead(II) nitrate. The balanced chemical equation is: $3\mathrm{PbS}(\mathrm{s}) + 8\mathrm{HNO}_{3}(\text{dilute}) \rightarrow 3\mathrm{Pb(NO}_{3}\mathrm{)}_{2}(\mathrm{aq}) + 3\mathrm{S}(\mathrm{s}) + 2\mathrm{NO}(\mathrm{g}) + 4\mathrm{H}_{2}\mathrm{O}(\mathrm{l})$ In this case, the gas produced is nitric oxide (NO).

   • Case 2: Reaction with concentrated $\mathrm{HNO}_{3}$ When lead(II) sulfide reacts with concentrated nitric acid, the sulfide ion ($S^{2-}$) is oxidized to sulfate ion ($\mathrm{SO}_{4}^{2-}$), which precipitates as insoluble lead(II) sulfate ($\mathrm{PbSO}_{4}$). The nitrate ion ($\mathrm{NO}_{3}^{-}$) is reduced to nitrogen dioxide ($\mathrm{NO}_{2}$). The balanced chemical equation is: $\mathrm{PbS}(\mathrm{s}) + 8\mathrm{HNO}_{3}(\text{conc.}) \rightarrow \mathrm{PbSO}_{4}(\mathrm{s}) + 8\mathrm{NO}_{2}(\mathrm{g}) + 4\mathrm{H}_{2}\mathrm{O}(\mathrm{l})$ In this case, the gas produced is nitrogen dioxide ($\mathrm{NO}_{2}$).

3. Analyze the properties of the possible gaseous products based on the options: Since the concentration of $\mathrm{HNO}_{3}$ is not specified, we must analyze the properties of both NO and $\mathrm{NO}_{2}$.

   Analysis for Nitric Oxide (NO):

   • A: paramagnetic: The total number of valence electrons in NO is 5 (from N) + 6 (from O) = 11. Since this is an odd number, NO must have an unpaired electron, making it paramagnetic. This statement is correct.
   • B: bent in geometry: NO is a diatomic molecule. All diatomic molecules are linear. Therefore, it does not have a bent geometry. This statement is incorrect.
   • C: an acidic oxide: NO is a neutral oxide. It does not react with acids or bases to form salts. Oxides like $\mathrm{N_2O_3}$, $\mathrm{NO_2}$, and $\mathrm{N_2O_5}$ are acidic. This statement is incorrect.
   • D: colorless: Nitric oxide (NO) is a colorless gas. This statement is correct.

   Analysis for Nitrogen Dioxide ($\mathrm{NO}_{2}$):

   • A: paramagnetic: The total number of valence electrons in $\mathrm{NO}_{2}$ is 5 (from N) + 2 * 6 (from O) = 17. Since this is an odd number, $\mathrm{NO}_{2}$ has an unpaired electron and is paramagnetic. This statement is correct.
   • B: bent in geometry: According to VSEPR theory, the central nitrogen atom in $\mathrm{NO}_{2}$ is bonded to two oxygen atoms and has one unpaired electron. This results in a bent or V-shaped molecular geometry. This statement is correct.
   • C: an acidic oxide: $\mathrm{NO}_{2}$ reacts with water to form nitric acid and nitrous acid ($2\mathrm{NO}_{2} + \mathrm{H}_{2}\mathrm{O} \rightarrow \mathrm{HNO}_{3} + \mathrm{HNO}_{2}$). It is therefore an acidic oxide. This statement is correct.
   • D: colorless: Nitrogen dioxide is a reddish-brown gas. This statement is incorrect.

4. Conclusion:

   • If the gas is NO (from dilute $\mathrm{HNO}_{3}$), the correct options are A and D.
   • If the gas is $\mathrm{NO}_{2}$ (from concentrated $\mathrm{HNO}_{3}$), the correct options are A, B, and C.

   Given that this is a multiple-choice question and typically such questions have a unique set of correct answers based on a standard reaction, the combination of options provided often helps to deduce the intended reaction conditions. The pair of properties (paramagnetic and colorless) uniquely describes NO. Therefore, it is most likely that the question refers to the reaction with dilute nitric acid, producing nitric oxide (NO).

   Thus, the gas produced is NO, which is paramagnetic and colorless.