The isomers of C₃H₈O are

Correct answer: 1-propanol and 2-propanol (Option A)

Explanation: The molecular formula C₃H₈O fits the two alcohol isomers of propanol:

• 1-propanol (CH₃CH₂CH₂OH) and 2-propanol (CH₃CHOHCH₃) have the same formula but differ by the position of the hydroxyl group, so they are structural (position) isomers.

• 1-propanol and 2-propanol — Correct.
• 1-propanol and 1-propanol — Same compound listed twice; not a pair of isomers.
• 2-propanol and 2-propanone — 2-propanone (acetone) has formula C₃H₆O, not C₃H₈O.
• 2-propanol and 1-propanol — This is the same pair as Option A; if forced to pick one, choose A.

Note: Another constitutional isomer of C₃H₈O is the ether methoxyethane (CH₃OCH₂CH₃), but it is not among the options.