Simplify Write the Answer in Exponential Form Without Negative Exponents $14 x ^ { 2 / 7 } \cdot 2 x ^ { - 9 / 4 }$

Multiple Choice

Simplify. Write the answer in exponential form without negative exponents.
- $14 x ^ { 2 / 7 } \cdot 2 x ^ { - 9 / 4 }$

A) $\frac { 7 } { x ^ { 55 / 28 } }$
B) $\frac { 28 } { x ^ { 55 / 28 } }$
C) $- 28 x ^ { 55 / 28 }$
D) $\frac { 1 } { 28 x ^ { 55 / 28 } }$