A block is attached to a spring of stiffness k. The other end of the spring is attached to a fixed wall. The entire system lie on a horizontal surface and the spring is in natural state. The natural length of the springs is `l_(0)` if the block is slowly lifted up vertically to a height `5/12 l_(0)` from its initial position :
A. The work done by the lifting force `=(kl_(0)^(2))/288+5/12mgl_(0)`
B. The work done by the spring force `=(kl_(0)^(2))/288`
C. The work done by the gravity `=5/12 mgl_(0)`
D. The work done by lifting force `=-5/12 mgl_(0)+(kl_(0)^(2))/288`
