Which of the following conclusions could be most properly drawn from the information given above? A. If one takes the medication more than an hour after ingesting grapefruit, its effectiveness is not diminished. B. Ingesting grapefruit after taking the medication does not diminish the effectiveness of the medication. C. There is only one type of pain receptor in the brain. D. The medication is fully effective only when it properly binds with its target pain receptors. E. It is not possible to design a medication for migraine headaches that can bond with the altered receptors.