When a rubber-band is stretched by a distance x, it exerts a restoring force of magnitude `F = ax + bx^2` where a and b are constants. The work done in stretching the unstretched rubber band by L is :

Options

A. `aL^2+bL_3`
B. `1/2(aL^2+bL^3)`
C. `(aL^2)/2+(bL^3)/3`
D. `1/2((aL^2)/2+(bL^3)/3)`