The most likely acid-catalysed aldol condensation products of each of the two aldehydes I and II are represented by the option (D). The product of aldol condensation of aldehyde I undergoes dehydration as the C=C double bond is in conjugation with C=O double bond. This leads to stability.
The product of aldol condensation of aldehyde II will not undergo dehydration as the C=C double bond is not in conjugation with C=O double bond due to presence of a quaternary C atom.
