Question

Which of the following substituted benzene derivatives would furnish three isomers when one more substitute is introduced?

• A.
• B.
• C.
• D. None of the above

Answer 1

The correct option is A

This condition is true only in option (a)

These isomers are positional isomers.
Isomers with a difference in the position of multiple bond/functional group/alkyl substituent on the same carbon skeleton (parent chain) are known as positional isomers.
The principal carbon chain remains the same in position isomers.

After an addition of substitute to (b), we get only two positional isomers and (c) does not show positional isomers.