Write in Exponential Form $- 6 \sqrt { 2 m ^ { 9 } }$

Multiple Choice

Write in exponential form. Assume all variables are positive real numbers.
- $- 6 \sqrt { 2 m ^ { 9 } }$

A) $- 6 \cdot 2 ^ { 1 / 2 } \mathrm {~m} ^ { 9 / 2 }$
B) $- 72 \mathrm {~m} ^ { 9 / 2 }$
C) $( - 6 \cdot 2 ) ^ { 1 / 2 } m ^ { 9 / 2 }$
D) $72 \mathrm {~m} ^ { 2 / 9 }$