It's either the last or the first one. I think the first one makes more sense though because it has already told you it created offspring so saying that again seem kind of redundant. Sorry I'm not sure
The answer is C. They lower the activation energy of an elementary step of a reaction This makes the reaction rate to increase since less energy is required to make a reaction occur.
it tells us of the specific amount of energy required to change the state of one mole of a substance either from solid to liquid or liquid to gas and vice versa without change in temperature