$$\frac{d^2x}{dy^2}$$ equals

A

$$\left(\frac{d^2y}{dx^2}\right)^{-1}$$

B

$$-\left(\frac{d^2y}{dx^2}\right)^{-1}\left(\frac{dy}{dx}\right)^{-3}$$

C

$$\left(\frac{d^2y}{dx^2}\right)\left(\frac{dy}{dx}\right)^{-2}$$

D

$$-\left(\frac{d^2y}{dx^2}\right)\left(\frac{dy}{dx}\right)^{-3}$$