Solve
-The Rectangle Has Width $7 x ^ { 3 }$

Multiple Choice

Solve.
-The rectangle has width $7 x ^ { 3 }$ feet and length $8 x ^ { 4 }$ feet. Find its area as an expression in $x$ . $($ Area $=$ length $\cdot$ width $)$

A) $56 \mathrm { x } ^ { 7 } \mathrm { sq } \mathrm { ft }$
B) $15 \mathrm { x } ^ { 12 } \mathrm { sq } \mathrm { ft }$
C) $15 x ^ { 7 } s q f t$
D) $56 \mathrm { x } ^ { 12 } \mathrm { sq } \mathrm { ft }$