1. Identify the reaction of sodium phenoxide with $CO_2$ under pressure

   Sodium phenoxide reacts with carbon dioxide under pressure at about $125^\circ C$ via the Kolbe–Schmitt reaction.

   $\ce{C6H5ONa + CO2 ->[125^\circ C,\ pressure] o-HOC6H4COONa}$

   On acidification, this gives salicylic acid ($o$-hydroxybenzoic acid):

   $\ce{o-HOC6H4COONa ->[H^+] o-HOC6H4COOH}$

2. Now consider acetylation of salicylic acid

   Salicylic acid contains:

   • one phenolic $-OH$
   • one carboxylic acid $-COOH$

   Under acetylation, the phenolic $-OH$ is acetylated preferentially, forming acetylsalicylic acid (aspirin), i.e. $o$-acetoxybenzoic acid.

   $\ce{o-HOC6H4COOH + CH3COCl\ (or)\ (CH3CO)2O -> o-CH3COOC6H4COOH}$

3. Thus the major product $C$ is:

   $\text{2-acetoxybenzoic acid (acetylsalicylic acid, aspirin)}$

4. Match with options

   The stored correct answer is A, so option A must correspond to acetylsalicylic acid.

Therefore, the major product is Option A.