According to the passage, now that scientists know...

Câu hỏi: According to the passage, now that scientists know that unusual neurons in certain people are the cause of migraines, they 

A know all they need to know about the cause of migraines. 

B have developed medicine to permanently reverse the neurons' charge.  

C still do not know exactly what causes the pain.   

D know that the defective neurons reside in the brain stem