Write the Number as a Product of a Real Number $i$

Multiple Choice

Write the number as a product of a real number and $i$ . Simplify the radical expression.
- $\sqrt{-245}$

A) $7 \mathrm{i} \sqrt{5}$
B) $-7 \sqrt{5}$
C) $-7 \mathrm{i} \sqrt{5}$
D) $7 \sqrt{5}$