In the Figure Below, How Much Gravel Is Necessary If $63 \mathrm { ft } ^ { 3 }$

Multiple Choice

In the figure below, how much gravel is necessary if it is to be laid to a depth of 9 inches? Round your answer to the nearest whole number.

A) $63 \mathrm { ft } ^ { 3 }$
B) $163 \mathrm { ft } ^ { 3 }$
C) $1,901 \mathrm { ft } ^ { 3 }$
D) $317 \mathrm { ft } ^ { 3 }$
E) $158 \mathrm { ft } ^ { 3 }$