The correct option is
A (1-Methylpropyl)cyclobutane
If the number of C-atoms in the ring and in the side chain are the same, then the name of ring appears in word root and side chain appears as secondary prefix.
![](https://df0b18phdhzpx.cloudfront.net/ckeditor_assets/pictures/943945/original_13.jpg)
The IUPAC name is (1-Methylpropyl)cyclobutane