Answer: Radioactive
Explanation:
Option A is correct.
A.The potential energy in the system is greatest at X.
A ball resting at the top of a hill will have greatest potential energy because when an object is at rest it tend to have greatest potential energy. When It moves from position X to Y the potential energy of the ball will decrease and its kinetic energy will increase.
Answer choices are listed below.
A.The potential energy in the system is greatest at X.
B.The kinetic energy in the system is greatest at X.