Read the Passage carefully and answer the questions.

The carbonyl group of aldehydes and ketones is highly polar. The positively charged carbon is readily attacked by electron-rich nucleophile and the negatively charged oxygen atom is attacked by an electro-deficient electrophile. Aldehydes and ketones undergo nucleophilic addition reactions in the presence of acid or a base. The mechanism involves attack of a nucleophile on the electron deficient carbonyl carbon to form a tetrahedral intermediate. A new bond is formed between the carbon and oxygen. Protonation of the anion furnished by the reaction medium yields a neutral addition product. The addition product is same whether the reaction is catalyzed by acid or a base. For example in the presence of base aldehydes and ketones react with hydrogen cyanide to form cyanohydrin.

During nucleophilic addition reaction the carbonyl carbon undergoes a change in hybridization from.......

$sp^2$ to $sp^3$

The correct answer is Option (1) → $sp^2$ to $sp^3$

In a nucleophilic addition reaction:

• The carbonyl carbon is initially sp² hybridized (trigonal planar).
• After the nucleophile attacks, it forms a tetrahedral intermediate, making the carbon sp³ hybridized.

Hence, Correct answer: sp² to sp³