let R be the region in the first quadrant between the graphs of $\displaystyle y=e^{-x}$, $\displaystyle y= sinx$ and the y-axis. The volume of the solid that results when R is revolved about the x-axis is

(A) -0.888

(B) -0.869

(C) 0.277

(D) 0.869

(E) 0.888

first thing i did was graph it on calculator then find where the graphs intersect but i forgot what to do from there