Simplify the Expression $\sqrt { 14 \mathrm {~m} ^ { 5 } } \cdot \sqrt { 7 \mathrm {~m} ^ { 9 } }$

Multiple Choice

Simplify the expression. Assume all variables represent positive real numbers.
- $\sqrt { 14 \mathrm {~m} ^ { 5 } } \cdot \sqrt { 7 \mathrm {~m} ^ { 9 } }$

A) $7 m ^ { 7 } \sqrt { 2 }$
B) $7 \mathrm {~m}^ 6 \sqrt { 2 }$
C) $14 m ^ { 4 } \sqrt { 7 }$
D) $7 \mathrm {~m} ^ { 8 }$