Answer: The correct answer is (a).
Step-by-step explanation:
The potential energy is due to the position of the object.
The kinetic energy is due to the motion of the object.
In the case of a basketball sitting on a shelf, the basketball posses the potential energy due to some height.
In the case of a dog running across a field, a dog has kinetic energy due to its motion.
In a case of a bowling ball rolling down a lane, there is kinetic energy due to the motion of the bowling ball.
In the case of a teenager riding their bike, there is kinetic energy due to the motion of the bike.
Therefore, the correct answer is (a).