Change the Exponential Expression to an Equivalent Expression Involving a Logarithm

Multiple Choice

Change the exponential expression to an equivalent expression involving a logarithm.
- $\log _ { 3 } 9 = 2$

A) $3 ^ { 2 } = 9$
B) $2 ^ { 3 } = 9$
C) $3 ^ { 9 } = 2$
D) $9 ^ { 2 } = 3$