Solve the Equation $\ln \mathrm{e}^{3 \mathrm{x}}=\pi \quad$ (Give the Exact Solution $\{3 \pi\}$

Multiple Choice

Solve the equation. Use natural logarithms. When appropriate, give solutions to three decimal places unless otherwise indicated.
- $\ln \mathrm{e}^{3 \mathrm{x}}=\pi \quad$ (Give the exact solution.)

A) $\{3 \pi\}$
B) $\{\pi-3\}$
C) $\left\{\frac{\pi}{3 e}\right\}$
D) $\left\{\frac{\pi}{3}\right\}$