Change the Exponential Expression to an Equivalent Expression Involving a Logarithm

Multiple Choice

Change the exponential expression to an equivalent expression involving a logarithm.
- $$7 ^ { 3 } = x$$

A) $\log _ { 3 } x = 7$
B) $\log _ { x } 7 = 3$
C) $\log _ { 7 } x = 3$
D) $\log _ { 7 } 3 = x$