Answer: Option (B) is the correct answer.
Step-by-step 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.