Correct Answer: C

Rationale: Nitroglycerin is contraindicated with Viagra due to their combined effects on lowering blood pressure, which can result in a severe drop and potentially life-threatening complications. Using both medications together can lead to hypotension, putting the patient at risk. Therefore, the presence of angina treated with nitroglycerin would make prescribing Viagra unsafe. Choices A, B, and D are not directly contraindicated with Viagra and can be managed concurrently with this treatment.

Correct Answer: A

Rationale: Alendronate should be taken with a full glass of water, and patients should remain upright for at least 30 minutes to prevent esophageal irritation and ensure proper absorption.

Correct Answer: A

Rationale: Tamsulosin relaxes the muscles in the prostate and bladder neck, leading to improved urinary flow and reduced symptoms of BPH.

Correct Answer: B

Rationale: Erectile function is primarily controlled by the parasympathetic nervous system, which facilitates the dilation of blood vessels in the penis. The parasympathetic nerves are responsible for vasodilation in the penis, allowing blood to enter and creating an erection. Sympathetic nerves, on the other hand, are responsible for ejaculation by causing contraction of the muscles around the vas deferens. Somatic nerves are involved in sensation and movement, not specifically in controlling blood supply to the penis. Spinal reflexes can play a role in the erectile process, but they are not directly responsible for controlling the venous blood supply.

Correct Answer: A

Rationale: Ibuprofen works by inhibiting cyclooxygenase (COX) enzymes, which play a key role in the production of prostaglandins that mediate pain and inflammation.