What is the name of this alkane?
a) 1-methylbutane
b) 2-methylbutane
c) 1,2-triethylethane
d) 1-dimethylpropane

Option (B) is the correct answer.

Explanation:

Numbering of carbon atoms will be done in such a way that the methyl group attached to the linear carbon chain will get least number.

Therefore, numbering will be done from left to right.

The given molecule shows that a methyl group is attached to the second carbon and rest there is a linear chain of four carbon atoms.

Thus, we can conclude that name of the given alkane is 2-methylbutane.

it is b that is the answer.