The correct option is A Directly proportional to the acceleration of the particle
Kinetic energy of a particle in motion E=12mv2
Differentiating w.r.t. x, we get
dEDx=12m×2vdvdx
=mv×dvdt×dtdx
=mv×av=ma.
So, the slope of kinetic energy - displacement curve is directly proportional to the acceleration of the particle.