Solve the Equation and Express the Solution in Exact Form $\ln \mathrm { e } ^ { \mathrm { x } } - \ln \mathrm { e } ^ { 4 } = \ln \mathrm { e } ^ { 5 }$

Multiple Choice

Solve the equation and express the solution in exact form.
- $\ln \mathrm { e } ^ { \mathrm { x } } - \ln \mathrm { e } ^ { 4 } = \ln \mathrm { e } ^ { 5 }$

A) $\{ 9 \}$
B) $\{ 20 \}$
C) $\{ - 1 \}$
D) $\{ 1 \}$