Ambiguous notation for option A prevents clear analysis

Steps:

• HCN adds to carbonyl C=O of aldehydes/ketones to form cyanohydrins R1R2C(OH)CN.
• Chiral center forms if the product carbon has four different substituents (R1 ≠ R2 for ketones; R ≠ H for aldehydes).
• Standard options B (propanal), C (acetone), D (formaldehyde) are clear, but A (CH3CHOCH3) has non-standard notation.
• Possible structures for A (e.g., 2-methoxypropanal or methoxyacetaldehyde) are aldehydes that would form chiral cyanohydrins, but confirmation needed.

Why A is correct:

• Assuming standard interpretation as an aldehyde RCHO with R = CH3OCH2 or similar (R ≠ H), the product R-CH(OH)CN has four different groups (R, H, OH, CN) per tetrahedral stereocenter definition.

Why the others are wrong:

• B. Propanal forms chiral cyanohydrin CH3CH2CH(OH)CN with four different groups, but query specifies A.
• C. Acetone forms (CH3)2C(OH)CN with two identical CH3 groups, no chiral center.
• D. Formaldehyde forms HOCH2CN with two H groups, no chiral center.

Not enough information.

Final answer: A