Use homeostasis to explain why you might throw up if you eat food that has gone bad.

Well it has an affect not only in the brain but also in your muscles and other parts, once it has that affect, your stomach thinks that the food you have just ate contained the homeostasis, so it troughs it out making you throw up

not 100% sure thats the answer 

You would modify how often you work out in reps and sets and also modify calorie intake

D) better spellers i would think