Answer :

The perimeter could be  C. 24? 

2 * 18 = 36
3 * 12 = 36
4 * 9 = 36
6 * 6 = 36

2 + 2 + 18 + 18 = 40
3 + 3 + 12 + 12 = 30
4 + 4 + 9 + 9 = 26
6 + 6 + 6 + 6 = 24

Geez, I haven't done this kind of a problem for a long time. Anyways, hoped  I helped! oo;