b to the second means b * b.
The short hand for b*b is b^2 on this editor or
c to the fourth means c * c * c *c
the short hand for c*c*c*c is c^4 on this editor or
The answer you want is b^2/c^4 in the answer box.
If this is wrong and you have choices, please list them and I will edit or put the answer in a comment.