4.已知{}x=2e^-ty=3e^2t=( )A. (3)/(2)B. -(3)/(2)C. -3D. -(1)/(3)

4.已知$\left\{\begin{matrix}x=2e^{-t}\\y=3e^{2t}\end{matrix}\right. $,则$\frac{dy}{dx}|_{t=0}=( )$

A. $\frac{3}{2}$

B. $-\frac{3}{2}$

C. -3

D. $-\frac{1}{3}$