Q: You are presented with the quiz "What causes an object to heat?"   But you don't know the answer, so you turn to your teacher to ask for hints. He says that "absorbing energy causes objects to heat" and "energy enters an ecosystem as sunlight".   So, what's the best answer to the question?

Select from:
 a). absorption
 b). photosynthesis
 c). electricity
 d). rays or beams
 e). colors of the spectrum
 f). absorbing sunlight
 g). absorbing ions
 h). It gets heated up
The answer is:
f).