Solve the Problem $15 \mathrm { in }$
B) $18 \mathrm { in }$

Multiple Choice

Solve the problem.
-A machine produces open boxes using square sheets of plastic. The machine cuts equal-sized squares measuring 3 inches on a side from each corner of the sheet, and then shapes the plastic into an open box by turning up the sides. If each box must have a volume of 675 cubic inches, find the length of one side of the open box.

A) $15 \mathrm { in }$ .
B) $18 \mathrm { in }$ .
C) 21 in.
D) $14 \mathrm { in }$ .