Solve the Problem $2 \sqrt { 7 } \mathrm { in }$

Multiple Choice

Solve the problem.
-Find the value for x in the rectangular prism. Use exact values.

A) $2 \sqrt { 7 } \mathrm { in }$ .
B) $3 \sqrt { 70 } \mathrm { in }$ .
C) $310 \mathrm { in }$ .
D) $\sqrt { 310 } \mathrm { in }$ .