At what point does a pendulum have the greatest kinetic energy? a) on the left b) on the right c) at the bottom d) at the top

At the bottom.

Explanation:

A pendulum possess two types of energies i.e. kinetic energy and the potential energy. It vibrates about its mean position. At extreme position, it will posses only gravitational potential energy or no kinetic energy. While at the bottom, its kinetic energy is maximum and minimum potential energy.

So, at the bottom a pendulum have the greatest Kinetic Energy. Therefore, the correct option is (c).