The correct option is A 2-Cyclopropyl-butane
The IUPAC name of the following compound is option A. Here alkyl group attached to ring contain more number of carbon, hence it is termed as derivative of alkane. So the longest chain is of four saturated carbons hence the suffix butane. The cyclopropyl group is in 2nd carbon so the IUPAC name comes out to be 2-cyclopropyl butane.