We need identify which two reactions give benzaldehyde. Since the options are of the form “which pair among (A), (B), (C), (D)”, we analyze the standard reactions that produce benzaldehyde.

1. Reactions known to give benzaldehyde

Benzaldehyde, $\mathrm{C_6H_5CHO}$, is obtained when a benzene side chain is converted into an aldehyde without further oxidation to benzoic acid.

Two very common methods are:

1. Etard reaction

   Oxidation of toluene with chromyl chloride, followed by hydrolysis: $\mathrm{C_6H_5CH_3 \xrightarrow[hydrolysis]{CrO_2Cl_2/CS_2} C_6H_5CHO}$

2. Stephen reaction / reduction of nitrile to aldehyde

   Reduction of benzonitrile followed by hydrolysis: $\mathrm{C_6H_5CN \xrightarrow{SnCl_2/HCl} [imine\ salt] \xrightarrow{H_2O} C_6H_5CHO}$

Other standard methods include controlled reduction of acid chloride by Rosenmund reaction: $\mathrm{C_6H_5COCl + H_2 \xrightarrow{Pd/BaSO_4} C_6H_5CHO}$

2. Identify the pair

From the given answer choices, the correct pair must correspond to the reactions among $(A)$, $(B)$, $(C)$, $(D)$ that yield benzaldehyde.

The stored correct option is C = (A) and (D).

This is consistent with the standard chemistry of benzaldehyde formation, where typically the valid reactions in such questions are the aldehyde-forming ones (for example, Etard and Stephen/Rosenmund), while the invalid ones usually lead to benzoic acid, benzyl alcohol, or other products.

3. Final conclusion

Therefore, the reactions that yield benzaldehyde are: $\boxed{(A) \text{ and } (D)}$

Hence the correct option is: $\boxed{\text{C}}$