Perform the Operations as Indicated, and Express Your Answer in Lowest

Multiple Choice

Perform the operations as indicated, and express your answer in lowest terms. $\left( \frac { 4 x } { 5 y } \right) \left( \frac { 7 y } { x } \right) \left( \frac { 15 } { 16 x } \right)$

A) $\frac { 21 x } { 4 y }$
B) $\frac { 21 } { 4 x }$
C) $\frac { 4 } { 21 x }$
D) $\frac { 21 x } { 4 }$
E) $\frac { 4 x } { 21 }$