A nurse is teaching a patient about the use of sildenafil [Viagra] for erectile dysfunction. Which statement by the patient indicates understanding of the teaching?

A. While sildenafil can cause erections, it does not typically lead to unwanted erections; it requires sexual stimulation to be effective. B. An erection lasting longer than 6 hours, known as priapism, is a serious side effect and requires immediate medical attention, indicating the patient understands this risk. C. Using nitroglycerin with sildenafil can lead to dangerous drops in blood pressure, and patients should be advised to avoid this combination. D. Sildenafil should be taken about 30 minutes to 1 hour before sexual activity for best results, not just 5 minutes prior.