Ellie Has Migraine Headaches on a Regular Basis

Ellie has migraine headaches on a regular basis. If she lies down as she feels a headache arising, she can prevent a migraine from developing. Her doctor prescribes a new medication that is 95 percent effective in preventing migraines. Ellie takes the medication but also continues to lie down when she feels a migraine coming on. Three months after he writes the prescription, the doctor asks her whether it has helped her. Ellie

A) wouldn't know, since she lies down when she feels a headache developing.
B) would probably say the medication works and she has not had a headache in three months.
C) would probably tell the doctor she took the medication but doesn't think it works.
D) wouldn't know because she is not a doctor.
E) None of these response options makes sense.