Final answer:
The client's intention to spend extra time in the sun while on nitrofurantoin indicates a need for additional teaching, as this can cause photosensitivity.
Step-by-step explanation:
Statement B, "I will spend extra time in the sun to get plenty of vitamin D." indicates the need for additional teaching about nitrofurantoin. Patients are usually advised to avoid excessive sunlight while taking nitrofurantoin due to the risk of photosensitivity, a possible side effect where an abnormal skin reaction occurs in response to sunlight exposure. Patients should also be made aware of the potential for developing secondary issues, such as a yeast infection, as a result of antibiotic therapy, and that they should complete the full course of antibiotics to prevent antibiotic resistance.