Simplify the Expression $4 \sqrt [ 7 ] { x ^ { 8 } y } - 3 x \sqrt [ 7 ] { x y }$

Multiple Choice

Simplify the expression. Assume all variables represent positive real numbers.
- $4 \sqrt [ 7 ] { x ^ { 8 } y } - 3 x \sqrt [ 7 ] { x y }$

A) $x \sqrt [ 7 ] { x y }$
B) $2 x \sqrt [ 7 ] { x y }$
C) cannot be simplified
D) $( 4 - 3 x ) \sqrt [ 7 ] { x y }$