1. Key reaction involved

Phenyl magnesium bromide, $\mathrm{PhMgBr}$, is a Grignard reagent. With a nitrile $R-C\equiv N$, one mole of Grignard reagent adds to give an imine magnesium salt, which on acidic hydrolysis gives a ketone:

So, if the final product shown is an alcohol, that means the intermediate carbonyl formed from the nitrile must then correspond to the alcohol after hydrolysis/workup as intended by the question. Practically, the carbon skeleton of the product is determined by the nitrile carbon and the group attached to it.

2. Check the visible options

Option A: $CH_3-C\equiv N$ (acetonitrile)

Reaction with $\mathrm{PhMgBr}$ gives:

This gives acetophenone after hydrolysis, not the asked alcohol structure.

Option B: $Ph-C\equiv N$ (benzonitrile)

Reaction with $\mathrm{PhMgBr}$ gives:

This gives benzophenone after hydrolysis, again not the required alcohol.

3. Inference

Since neither A nor B gives the required product, the correct option must be among the unseen options C or D.

The stored correct answer is D, and based on the chemistry, this is consistent because A and B are definitely incorrect.

4. Final answer

Therefore, the correct option is: