Correct Answer: C

Rationale: The correct answer is C: Hyperpigmentation and hypotension. These findings are classic signs of Addison disease, caused by adrenal insufficiency. Hyperpigmentation results from increased ACTH stimulating melanin production, and hypotension occurs due to mineralocorticoid deficiency. Choices A, B, and D are incorrect. Arrested height and increased weight are not typical of Addison disease. Thin, fragile skin and multiple bruises are seen in conditions like Cushing's syndrome, not Addison disease. Blurred vision and enuresis are not characteristic symptoms of Addison disease.

Correct Answer: B

Rationale: Metatarsus adductus is a condition where the front part of the foot is turned inward. It is often caused by the baby's position in the womb, leading to pressure on the foot during fetal development. Choice A is incorrect as metatarsus adductus is not primarily caused by a genetic defect in the bones. Choice C is incorrect as the cause of metatarsus adductus is known to be related to intrauterine positioning. Choice D is incorrect as metatarsus adductus specifically pertains to the foot and not the hip.

Correct Answer: B

Rationale: The sweat chloride test is the gold standard diagnostic test for cystic fibrosis as it measures the concentration of chloride in sweat. In cystic fibrosis, there is an abnormal transport of chloride across epithelial membranes, leading to elevated sweat chloride levels. A chest X-ray may show characteristic changes in the lungs associated with cystic fibrosis, but it is not a definitive diagnostic test. Pulmonary function tests assess lung function but do not specifically diagnose cystic fibrosis. Sputum culture may identify respiratory infections but does not confirm the diagnosis of cystic fibrosis.

Correct Answer: C

Rationale: Delayed physical growth is a common finding in children with symptomatic cardiac malformations. This occurs due to insufficient oxygenation and nutrient supply, which can affect overall growth and development. Mental retardation (Choice A) is not typically associated with symptomatic cardiac malformations. Inherited genetic factors (Choice B) may contribute to the development of cardiac malformations but are not a common finding in affected children. Clubbing of the fingertips (Choice D) is more commonly associated with chronic respiratory or cardiovascular conditions, rather than symptomatic cardiac malformations.

Correct Answer: B

Rationale: The correct answer is B: Diarrhea. Rotavirus infection commonly presents with symptoms such as watery diarrhea, fever, vomiting, and abdominal pain. However, diarrhea is the hallmark symptom of rotavirus infection, often leading to dehydration in children. Abdominal pain (choice A) can also be present but is not as specific to rotavirus infection as diarrhea. Constipation (choice C) is not a typical symptom of rotavirus infection. While vomiting (choice D) can occur in rotavirus infection, it is more commonly associated with other gastrointestinal conditions.