Write the Expression in the Form Bi, Where B Is $\sqrt { - 25 }$

Multiple Choice

Write the expression in the form bi, where b is a real number.
- $\sqrt { - 25 }$

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