Sorry I'm not too sure but I know that you can probably find it using this formula:
Area = (1/2)(a)(b)(sin(C)) with C being the angle in the middle of both lines a and b in a triangle
Since a rhombus is pretty much two similar triangles....
Area = ((1/2)(6)(6)(sin6)) x 2
should give you the exact area
Sorry that I couldn't give an exact answer, I'm not too sure what in is because we were probably not taught the same things. Does it mean inch or is it supposed to be Ln? Anyways, whatever it means, maybe you could calculate each option's value and see which one is the same answer as the calculation I talked about above?