Classifying alcohol type and planarity from ester structure

Steps:

• Identify ester linkages in Z to separate alcohol (X) and acid (Y) fragments.
• Examine carbon attached to oxygen in X fragment: two alkyl groups confirm secondary alcohol.
• Check X structure in Z: cyclic or chain without sp2 carbons, so non-planar.
• Check Y structure in Z: dicarboxylic chain without conjugation or rings, so non-planar.

Why A is correct:

• Secondary alcohol defined by carbon with two alkyl and one OH/hydrogen; non-planar for both X and Y as aliphatic chains lack pi bonds for planarity.

Why the others are wrong:

• B: X is non-planar, not planar (no aromatic ring).
• C: Alcohol is secondary, not tertiary (lacks three alkyl groups).
• D: Alcohol is secondary, not tertiary; Y is non-planar, not planar.

Final answer: A