A cantilever beam carries a uniformly distributed total load W over its whole length and a concentrated upward load W at its free end. The net vertical deflection at the free end is

A

Zero

B

$$\frac {5.WL^3}{24 EI}$$ downwards

C

$$\frac {5.WL^3}{24 EI}$$ upwards

D

$$\frac {5.WL^3}{48 EI}$$ downwards