A male client reports to the nurse that he took sildenafil for erectile dysfunction but did not achieve an erection. Which of the following considerations should the nurse evaluate to determine possible reasons for the lack of response?

A. The client's level of sexual stimulation Sildenafil requires sexual stimulation to be effective. It enhances blood flow to the penis but does not automatically cause an erection. The client should be educated that adequate sexual arousal is necessary for the medication to work. B. If taken with a high-fat meal, the medication is more effective Taking sildenafil with a high-fat meal can actually delay its absorption and reduce effectiveness. Clients should be advised to take it on an empty stomach or with a light meal for optimal results. C. The client's recent consumption of caffeine Caffeine intake does not interfere with sildenafil’s effectiveness. However, excessive caffeine consumption may contribute to vasoconstriction, which could indirectly affect erectile function. D. If client took an additional dose to achieve an erection Taking an extra dose of sildenafil is not recommended and can increase the risk of serious side effects such as hypotension, priapism (prolonged erection), and cardiovascular complications. The client should follow prescribed dosing guidelines.