option (C) is correct
The ball rebounds to a height h2= 4cm.
So velocity with which it rebounds is v2= (2gh2)^1/2
Similarly the velocity with which the ball trikes the floor ahter falling from height h1=25cm will be
v1= (2gh1)^1/2
Hence coefficient of restitution e = v2/v1= (h2/h1)^1/2=(4/25)^1/2=2/5=0.4