Correct Answer: A

Rationale: The correct teaching point that the physician should include when explaining Duchenne muscular dystrophy to the parents is that 'Your child may develop breathing difficulties as the disease progresses.' Duchenne muscular dystrophy is a progressive condition that affects muscle strength, including respiratory muscles, leading to breathing difficulties as the disease advances. Choice B is incorrect because while physical therapy and exercise can help maintain muscle function and mobility, they do not cure the condition. Choice C is incorrect because Duchenne muscular dystrophy is a genetic disorder with no known cure. Choice D is incorrect as Duchenne muscular dystrophy is primarily characterized by a lack of dystrophin protein due to genetic mutations, not inflammation in the muscles.

Correct Answer: A

Rationale: The correct answer is A: Weight gain, mood changes, and nausea are common side effects of oral contraceptives. Weight gain may occur due to fluid retention or changes in metabolism. Mood changes can be caused by hormonal fluctuations. Nausea is a common side effect that usually improves after a few months of use. Choices B, C, and D are incorrect because they do not reflect common side effects associated with oral contraceptives. Increased appetite, insomnia, breast tenderness, headaches, dizziness, fatigue, hair loss, and joint pain are not typically reported side effects of oral contraceptives.

Correct Answer: B

Rationale: The correct answer is B: 'Use of nitrates.' Sildenafil (Viagra) is contraindicated in patients taking nitrates due to the risk of severe hypotension. Nitrates and sildenafil both cause vasodilation, and their combined use can lead to a dangerous drop in blood pressure. Choices A, C, and D are incorrect because a history of hypertension, recent use of antihypertensive medications, or a history of peptic ulcer disease are not direct contraindications for using sildenafil.

Correct Answer: A

Rationale: The correct answer is to instruct the patient to take the medication at night to avoid muscle pain. Statins are known to potentially cause muscle pain or weakness; taking the medication at night can help reduce the incidence of these side effects. Option B is incorrect because the timing of statin administration is not related to its effectiveness throughout the day. Option C is a general precaution when taking medications but not the most important instruction specific to statins. Option D is incorrect as taking the medication with a high-fat meal can actually decrease its absorption.

Correct Answer: D

Rationale: The correct answer is D: B and T cell deficits. Severe combined immune deficiency (SCID) syndrome affects both B and T cells, leading to a severe impairment in the immune system's ability to fight infections. Choice A (B cell deficits) is incorrect because SCID affects not only B cells but also T cells. Choice B (T cell deficits) is incorrect as SCID is characterized by deficits in both B and T cells. Choice C (Complement deficits) is incorrect as SCID primarily involves B and T cell deficiencies rather than complement deficiencies.