Correct Answer: A
Explanation:
A Grignard reagent is highly reactive species, provides a nucleophilic carbon which can be used for bonding to another carbon in both aldehyde and ketones. (The carbon bonded to magnesium in the Grignard reagent is nucleophilic, being the more electronegative end of the bond with magnesium.) For example, Grignard reagent carbon reacts with electropositive carbonyl carbons. Grignard reagents can’t be used in the presence of acidic protons. The acid in the mechanism above is only applied in the reaction’s last stage.