The Volume of a Box Is $3 p^{4}+27 p^{3}+42 p^{2}$ the Height Is

Multiple Choice

The volume of a box is $3 p^{4}+27 p^{3}+42 p^{2}$ . The height is $p$ , and the width is $p+7$ . What is the length?

A) $p^{2}+6$
B) $3 p^{2}+6 p$
C) $3 p+6$
D) $3 p^{3}+6 p^{2}$