A patient with bipolar disorder and who takes lithium telephones the nurse at the clinic to say, ...

A patient with bipolar disorder and who takes lithium telephones the nurse at the clinic to say, I've had severe diarrhea for 4 days. I feel very weak and unsteady when I walk. My usual hand tremor has gotten worse. What should I do?
 
  The nurse should advise the patient:
 
  a. Restrict food and fluids for 24 hours, and stay in bed.
  b. Have someone bring you to the clinic immediately.
  c. Drink a large glass of water with 1 teaspoon of salt added.
  d. Take an over-the-counter antidiarrheal medication hourly until the diarrhea subsides.