An agonist will active receptors, causing a physiological response. (Pretty much, it acts like a neurotransmitter). On the other hand, an antagonist will BLOCK a receptor, preventing a neurotransmitter from binding on that receptor, therefore blocking a physiological response.
Agonist --> acts like a neurotransmitter and elicits a responseAntagonist --> BLOCKS a neurotransmitter by binding on to the receptor, therefore blocking a response.
The answer to your question is B because it stores urine from your kidneys .
Placebos are fake medications or treatments that can trick your brain into thinking it's better. Often someone will think they are very sick when they actually aren't, and that's dangerous for the mind so people will give them fake medications. Its of cures and things atet will help seasickness and motion sickness are placebos. You could have a moral dilemma about wether it's actually helping you or if it just feels like it does.
The answer is false because conserving water only saves water, it does not prevent water pollution