This doesn't seem like much of a biology question but more of a chemistry one :P
But to answer your question, as the temperature of the water molecules rises, the chemical bonds holding them together begin to fall apart, causing the structure of the ice to fall apart.
When water is evaporated, the chemical bonds holding the water molecules together becomes non-existent, and the water becomes a vapour in which molecules float independent of each other <span />
The answer is
B) a flowerpot falling from a balcony.
This is the answer because potential energy is basically when something is standing still. Kinetic energy is the opposite, its when something is moving. So the flowerpot was still but something knocked it over and the potential energy was turned into kinetic energy. In option A, the kinetic energy is being turned into potential energy singe the car stopped moving. In option C, the cow is just storing potential energy and it is not being transformed into kinetic energy since the cow is not moving. Option D is not the answer because once again, this says the bike is slowing down, which means that the kinetic energy is decreasing and being turned into potential energy.
Well, in a way it is true, as, chloroplasts are the reason why plants photosynthesize. So, with the photosynthesis, it releases oxygen, which is the power generator for life on Earth, as we breathe in oxygen.