Given a scientific question, generate an incorrect answer to the given question. The incorrect answer should be a plausible alternative to the correct answer. The answer should be some other item belonging to the same category as the correct answer but should be incorrect.

[Q]: What are intervertebral discs made of?
[A]: intercartilage

[Q]: What happens during the process of digestion?
[A]: excretion of food

[Q]: Drilling wells into hot rocks to release hot water or steam is an example of what kind of power plant?
[A]:
hydroelectric