Helpp pls, with explanation

B .

Explanation:

Elastic potential energy stored in a spring is given by;

E=1/2*k*{Δl}²  where

k= spring constant

Δl = change is length of spring

if k is different the energy stored in the system is different. This is true also in the case where Δl is different.

For a parallel system, springs help each other to carry the weight. The stiffness doubles up to mean ;

k parallel =2k

and

Δl parallel = 1/2 Δl

so;

E in one spring = 1/2*k*{Δl}²{a}

Using {a} this in the parallel system;

E parallel = 1/2 * 2k * {1/2Δl}²

                = 1/2 * 2* k* 1/4 *{Δl}²

                = 1/2 E in one spring

Answer : Ep / 2

a and c

c is 100% but i am confused in a