Identifying carbonyl type and chiral centers in X

Steps:

• Locate the carbonyl (C=O) group in the structure.
• Determine if the carbonyl carbon is attached to one H and one R group (aldehyde) or two R groups (ketone).
• Scan all carbons for tetrahedral atoms bonded to four different substituents, indicating chirality.
• Count the chiral centers: one such carbon is present.

Why D is correct:

• A ketone has the carbonyl between two carbon atoms (general formula RCOR'), and the structure shows exactly one chiral carbon with four distinct groups attached.

Why the others are wrong:

• A: Aldehyde requires terminal C=O with H; structure has internal carbonyl.
• B: Ketone is correct, but structure has one chiral center, not zero.
• C: Aldehyde is incorrect; carbonyl is not terminal.

Final answer: D