A nurse is reinforcing teaching with a client who has a prescription for sildenafil to treat erectile dysfunction. Which of the following statements by the client indicates an understanding of the teaching?

A. "This medication will protect me from sexually transmitted diseases.": Sildenafil does not prevent sexually transmitted diseases. B. "I will avoid eating fatty foods, while I take this medication.": Fatty foods can delay the absorption and effectiveness of sildenafil. C. "I should take this medication twice each day.": Sildenafil is typically taken as needed, not twice daily. D. "I can expect to have constipation while I take this medication.": Constipation is not a known side effect of sildenafil.