In this problem, you don't have to solve anything or write such a equation. You just need to know the nature of force, energy and velocity of the object when it reaches the highest point.
In the problem, it is said that there exists a friction force. Hence, the total force is no longer

. By Newton's law of motion, the acceleration is longer always

. So, (A) is wrong.
Next, since there is friction, the energy dissipates in the process. There is no way the rock attain the same speed (kinetic energy), nor even greater than initial speed before returning to the starting point. So, (D) and (E) are wrong.
Now, (B) and (C) come together. Well, we know that at the highest point of motion, the velocity of object is zero. So, at that point, the friction force is zero. As if it is free fall motion, the acceleration at that point is

. So, (B) is right, and (C) is wrong.
The correct answer is (B) ,and by stat, 67 of 100 people got the right answer.