Assertion (A): Pentane and `3` methyl pentane are chain isomers.
Reason (R ): Pentane is a straight-chain alkane while `3`-methyl pentane is branched-chain alkane.

Options

A. both (A) and (R ) are true and (R ) is the correct explanation for (A).
B. both (A) and (R ) are true and (R ) is not the true explanation for (A)
C. (A) is true, but (R ) is false.
D. (A) is false and (R ) is true.

Answer

D

Explanation

(A) is false. They are homologues, since the number of `C` atoms in pentane and `3` methyl `1` pentane is not same, they cannot be isomers. (R ) is true.