As a pendulum swings from the bottom position to the top position kinetic energy is changed into potential energy

mechanical energy is changed into radiation

radiation is changed into friction

potential energy is changed into kinetic energy

Actually Welcome to the Concept of the Power and Energy.

As a pendulum swings from the bottom position to the top position, it gains a height which means it gains the Potential energy.

hence we can say that, kinetic energy is changed into potential energy.

So, the Option A.) is correct.