Let $z = e ^ { x y }$ , Where X = T Cos T and Y =

Multiple Choice

Let $z = e ^ { x y }$ , where x = t cos t and y = t sin t.When t = 0, $\frac { d z } { d t }$ is

A) $\pi$
B) $- \pi$
C) $- 1$
D) 0
E) 1