Given below are two statements: 

Assertion (A): Among isomeric pentanes, 2,2-dimethylpropane has the highest boiling point.
Reason (R): Branching does not affect the boiling point.

1. Both (A) and (R) are true and (R) is the correct explanation of (A).
2. Both (A) and (R) are true but (R) is not the correct explanation of (A).
3. Both (A) and (R) are false.
4. (A) is true but (R) is false.

Hint: Boiling point is inversely proportional to branching

As branching increases, the boiling point of alkane decreases in comparable molecular masses. The structures of pentane and  2,2-dimethylpropane are as follows:

As branching increases the boiling point of the compound decreases but in compounds with comparable molar masses. Hence, 2,2-dimethylpropane boiling point is lower than pentane because it has a higher branching than pentane.

Thus, both assertion and reason are not correct.