Answer:
a. The balls initial kinetic energy.
Explanation:
As we know that initially speed is given to the ball downwards so that it moved in a circle so then finally reached to point B
Now given that point B is higher than the initial position A from which it is projected
Now by energy conservation we know that
[tex]K_i + U_i = K_f + U_f[/tex]
since final speed is zero so we have
[tex]K_i + mgh_a = 0 + mgh_b[/tex]
[tex] h_b = h_a + \frac{K_i}{mg}[/tex]
so from above equation we can say that since initial kinetic energy is given to the ball so it will be able to reach the point which is higher than its initial position
so correct answer is
a. The balls initial kinetic energy.