Give the Answer in Exact Form $$e ^ { 2 x } - 8 e ^ { x } + 15 = 0$$

Multiple Choice

Give the answer in exact form.
- $$e ^ { 2 x } - 8 e ^ { x } + 15 = 0$$

A) $\left\{ \mathrm { e } ^ { 5 } , \mathrm { e } ^ { 3 } \right\}$
B) $\left\{ \frac { 5 } { e } , \frac { 3 } { e } \right\}$
C) $\{ \ln 5 , \ln 3 \}$
D) $\{ \ln ( - 5 ) , \ln ( - 3 ) \}$