Examine Statement (I)

Statement (I): $\mathrm{SiO}_2$ and $\mathrm{GeO}_2$ are acidic while $\mathrm{SnO}$ and $\mathrm{PbO}$ are amphoteric in nature.

Group 14 oxides show a trend in acid-base character down the group:

• $\mathrm{CO}_2$ and $\mathrm{SiO}_2$ are acidic.
• $\mathrm{GeO}_2$ is generally considered acidic to weakly amphoteric, but in standard JEE treatment it is commonly grouped with the acidic oxides of the upper members.
• $\mathrm{SnO}$ and $\mathrm{PbO}$ are amphoteric.

So the statement matches the standard trend taught for Group 14 elements.

Hence, Statement (I) is true.

Examine Statement (II)

Statement (II): Allotropic forms of carbon are due to property of catenation and $\mathrm{p}\pi-\mathrm{d}\pi$ bond formation.

• Carbon does show catenation, which helps in forming long chains and networks.
• However, carbon does not have vacant d-orbitals in its valence shell, so $\mathrm{p}\pi-\mathrm{d}\pi$ bonding is not possible for carbon.
• The existence of allotropes of carbon (diamond, graphite, fullerene, etc.) is due mainly to catenation and the ability of carbon to form different types of covalent bonding and hybridisation, not $\mathrm{p}\pi-\mathrm{d}\pi$ bonding.

Hence, Statement (II) is false.

Choose the correct option

• Statement I: True
• Statement II: False

Therefore, the correct option is:

$\boxed{\text{D: Statement I is true but Statement II is false}}$

Comparison with stored correct answer

Stored correct answer: D

My derived answer also is D, so they agree.