The potential energy is stored in the wrecking ball, but as it swings towards the wall, the potential energy is converted into kinetic energy.
Thus, while the wrecking ball moves towards the wall, the kinetic energy will increase.
Hence, increase in the correct answer.
The kinetic energy of the wrecking ball when strikes the wall is transferred to the wall.
Hence, the kinetic energy of the wrecking ball is transferred to the wall in form of heat energy.