Please please explain why that answer is correct and why i got it wrong!

Me with this i need to get the answer quickly.

Aclient, prescribed dextroamphetamine for attention deficit hyperactivity disorder (adhd), has developed a common adverse effect of the medication since beginning therapy. which initial intervention should the client be encouraged to implement? a. increase fiber intake. b. take an over-the-counter (otc) laxative daily. c. take metronidazole. d. take diphenoxylate hydrochloride.

In which book word demography is used for first time