Correct Answer: B

Rationale: Melena indicates bleeding from the upper GI tract. The black, tarry appearance of the stool results from the partial digestion of blood as it passes through the intestines, typically originating from sources like the stomach or duodenum. Lower GI bleeding usually presents as bright red blood in the stool, originating from sources like the colon or rectum. Choices A, C, and D are incorrect because melena specifically points to upper GI bleeding rather than issues in the perianal/rectal area, lower GI tract, or hemorrhoids/anal fissures.

Correct Answer: C

Rationale: The correct answer is C. Hepatitis A typically presents with a rapid onset, early fever, and nausea/vomiting. These are common clinical features seen in patients with hepatitis A. A pruritic rash is not commonly associated with hepatitis A, so choice C is incorrect. Choice A and B alone are not sufficient to cover all the clinical features of hepatitis A.

Correct Answer: C

Rationale: The correct answer is C, Respiratory syncytial virus (RSV). RSV is the leading cause of bronchiolitis, a common respiratory condition in infants that results in inflammation of the small airways in the lung. It is highly contagious and can cause severe respiratory distress in young children, particularly those under 2 years old. Choice A, Adenovirus, is not the most common cause of bronchiolitis in infants. Choice B, Influenza virus, may cause respiratory infections but is not the primary cause of bronchiolitis. Choice D, Parainfluenza virus, can cause croup and other upper respiratory infections but is not the main cause of bronchiolitis in infants.

Correct Answer: D

Rationale: Correct! Typical signs of appendicitis include fever, vomiting, and tachycardia due to infection and inflammation. These clinical manifestations are commonly observed in patients with appendicitis. Hyperactive bowel sounds are not typically associated with appendicitis, so they are not expected findings in this situation. Therefore, the correct answer is 'All of the above.'

Correct Answer: C

Rationale: The correct answer is C: Hyperlipidemia. Children with nephrotic syndrome often present with hyperlipidemia due to altered lipid metabolism, making it a primary concern in these patients. Hypotension (choice A) is not a primary concern in nephrotic syndrome. Hyperkalemia (choice B) and hypocalcemia (choice D) are not typically associated with nephrotic syndrome and are less likely to be primary concerns in these patients.