Correct Answer: B

Rationale: The correct answer is B. Finasteride (Proscar) is used in the treatment of benign prostatic hyperplasia to improve urinary flow and decrease symptoms of urinary retention by reducing the size of the prostate gland. Choice A is incorrect because although finasteride may reduce the size of the prostate gland, the expected outcome relevant to the patient's symptoms is improved urinary flow rather than a specific change in gland size. Choice C is incorrect because finasteride actually decreases the production of prostate-specific antigen (PSA) due to its mechanism of action. Choice D is incorrect because although improved urinary flow may lead to a reduction in nocturnal awakenings, the main expected outcome of finasteride treatment is related to urinary symptoms.

Correct Answer: A

Rationale: The correct answer is A: "It inhibits bone resorption, which helps maintain bone density." Bisphosphonates work by inhibiting bone resorption carried out by osteoclasts, thereby preventing the breakdown of bones and helping to maintain or increase bone density in patients with osteoporosis. Choices B, C, and D are incorrect because bisphosphonates do not directly stimulate new bone formation, increase calcium absorption in the intestines, or decrease calcium excretion by the kidneys.

Correct Answer: C

Rationale: When taking isoniazid and rifampin for active tuberculosis, patients should be taught that an improvement in symptoms will likely be noticed within 2 to 3 weeks. Choice A (48 hours) is too soon to expect significant improvement in symptoms. Choice B (a week to 10 days) is also too early for noticeable improvement with this medication regimen. Choice D (4 to 6 weeks) is too far out to expect a noticeable improvement in symptoms.

Correct Answer: C

Rationale: The correct answer is C. In assessing a child for migraines, asking about food allergies is least likely to yield data that will confirm or rule out migraines as the cause of his headaches. Food allergies are unrelated to the typical symptoms and triggers of migraines, such as family history, associated symptoms like nausea and vomiting, and pain-free intervals between headaches. Therefore, in this scenario, focusing on food allergies is less relevant for identifying migraines as the cause of the boy's headaches.

Correct Answer: C

Rationale: The correct answer is C. Oral contraceptives can be less effective when taken with certain antibiotics as they may interfere with the effectiveness of the contraceptive. It is important for patients to be aware of this interaction to consider additional contraceptive methods during antibiotic therapy. Choices A and B are incorrect as no contraceptive method is 100% effective, and oral contraceptives typically require a period of time to reach full effectiveness. Choice D is incorrect as taking oral contraceptives with food does not significantly impact their effectiveness.