Consider the following general reaction of carbonyl group with a reagent?

Explanation

C is the correct option , as we can clearly see nucleophile being added into the reactant thus, making it nucleophilic addition reaction. The following excerpt is from PTB. Nucleophilic Addition Reactions of Aldehydes and Ketones: As a result of the unsymmetrical electronic distribution about the carbonyl group, the nucleophilic reagent can start the initial attack on the carbon. It appears that whether the initial attack is to be by a nucleophilic reagent or by an electrophilic reagent depends upon a particular reaction andupon the conditions under which that reaction is carried out. Therefore, most of the reactions of the carbonyl group will be considered to be nucleophilic addition reactions.