A body of mass M is attached to the lower end of a metal wire, whose upper end is fixed. The elongation of the wire is l.
a) Loss in gravitational potential energy of M is Mg l b) The elastic potential energy stored in the wire is Mgl c) The elastic potential energy stored in the wire is 1/2 Mgl d) Heat produced is 1/2 Mgl

Options

A. only a, b are true
B. only b, c are true
C. only a, d are true
D. only a, c, d are true

Answer

D