A nurse is speaking on the phone to a client on the phone who is pregnant and taking iron supplements for iron-deficiency anemia. The client reports that her stools are black but she has no abdominal pain or cramping. Which of the following responses by the nurse is appropriate?

A. "Go to the emergency room and your provider will meet you there.": Black stools can be a sign of gastrointestinal bleeding, but in the absence of pain, cramping, or other symptoms, emergency evaluation is not necessary. This response may cause unnecessary anxiety. B. "Come to the office and we will check things out.": Routine office evaluation is not required for black stools caused by iron supplements when the patient is otherwise asymptomatic. C. "This is expected because of the way iron is broken down during digestion.": Oral iron commonly causes dark or black stools due to oxidation of iron in the gastrointestinal tract. This is a harmless and expected side effect, and the patient can be reassured while continuing therapy. D. "What else have you been eating?": While diet can affect stool color, in this context the most likely cause is iron supplementation. Asking about diet is not necessary unless additional symptoms suggest an alternative cause.