Use Definite Integrals to Find the Area of the Surface $f ( x ) = e ^ { - x }$

Multiple Choice

Use definite integrals to find the area of the surface of revolution obtained by revolving $f ( x ) = e ^ { - x }$ around the x-axis on the interval [-1, 2].

A) 6.33 $\pi$
B) 8.33 $\pi$
C) 9.33 $\pi$
D) 10.33 $\pi$