A trench needs to be at least 63 feet below ground level. This means it needs to be more than 3 1/2 times its current depth. This depth is represented by the inequality 3 1/2d < -63, where d is the current depth of the trench. Select from the drop-down to correctly interpret the solution of this inequality.

The current depth of the trench is Choose... feet below ground level.
A. At most 18
B. Deeper than 18
C. less than 18