AS level physics forces and motion question

A ball is thrown at an angle of 30° to the horizontal. The initial kinetic energy of the ball is K. Air resistance has a negligible effect on the motion of the ball.What is the kinetic energy of the ball at the maximum height?
A. 0
B. 0.25K
C. 0.75K
D. 0.87K

The answer is C but I don't understand how to get the answer. Please help!

Simple trig for the velocity. At the peak, the vertical velocity is zero and the horizontal velocity is unchanged (so resolve the initial velocity).

Simple trig for the velocity. At the peak, the vertical velocity is zero and the horizontal velocity is unchanged (so resolve the initial velocity).

But what do I do after getting the initial velocity?

The initial velocity is v (30 degrees to the horizontal), so what is the horizontal velocity and then how are the KEs related?

The initial velocity is Kcos30 I think, and KE is directly proportional to speed^2