Multiply, and Then Simplify If Possible $( \sqrt { 2 x } - 3 \sqrt { 7 } ) ( \sqrt { 2 x } - 3 \sqrt { 3 } )$

Multiple Choice

Multiply, and then simplify if possible. Assume all variables represent positive real numbers.
- $( \sqrt { 2 x } - 3 \sqrt { 7 } ) ( \sqrt { 2 x } - 3 \sqrt { 3 } )$

A) $2 x - 3 \sqrt { 6 x } - 3 \sqrt { 14 x } + 9 \sqrt { 7 }$
B) $2 x - 3 \sqrt { 42 x } + 9 \sqrt { 21 }$
C) $4 x ^ { 2 } - 3 \sqrt { 6 x } - 3 \sqrt { 14 x } + 9 \sqrt { 21 }$
D) $2 x - 3 \sqrt { 6 x } - 3 \sqrt { 14 x } + 9 \sqrt { 21 }$