Simplify the Radical Expression $\sqrt { 98 x ^ { 2 } }$

Multiple Choice

Simplify the radical expression. Assume that all variables represent positive real numbers.
- $\sqrt { 98 x ^ { 2 } }$

A) $98 x$
B) $7x \sqrt { 2 }$
C) $7 \sqrt { 2 x }$
D) $2 x ^ { 2 } \sqrt { 7 }$