The regulation of the bodies internal environment is called homeostasis. And there are so many ways that affect homeostasis in the human body and to name three: first is the heat where we seat when we get too hot. Second, is the cold where we shiver when we get too cold and the third is the fluid intake where dehydration can kill.
I mean, there's plenty of differences between muscle and nerve cells. For one, they serve different functions. Nerve cells react and send stimuli rapidly through action potentials, functioning in the nervous system and allowing the brain to communicate with the rest of the body, while muscle cells allow muscles to move. Another difference is the structure of the cells, with nerve cells having dendrites, axons, and neurotransmitters to assist in the firing of action potentials. You're going to have to be a little more specific, I can't really help you any more with such a broad question.
The answer is B. Scientist repeat the experiments in order to prevent bias.
Brainlest answer is always appreciated!