Assertion: Alkanes with more than three carbon atoms exhibit chain isomerism.
Reason: Branching of the carbon atom chain is necessary for exhibiting chain isomerism.
(a) A is correct, R is correct and R is a correct explanation of A.
(b) A is not correct,R is correct and R is not a explanation for A.
(c) Both A and R are wrong.
(d) R is correct reason but A is wrong.