Directional derivative of $$U = 2x^{3}y - 3y^{2}z$$ at P(1, 2, -1) in a direction towards Q(3, -1, 5) is

A

$$\frac{-90}{7}$$

B

$$\frac{30}{7}$$

C

$$\frac{90}{49}$$

D

None of the above