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.

Correct Answer: B

Rationale: Vomiting and poor appetite are common symptoms of neuroblastoma, a malignancy that arises from neural crest cells in the adrenal glands or sympathetic nervous system. This tumor can cause abdominal swelling due to its location and size, leading to symptoms like vomiting and decreased appetite. The presence of a maculopapular rash on the palms (Choice A) is not a typical finding associated with neuroblastoma. Irritability and failure to thrive (Choice C) are nonspecific symptoms that can be seen in various conditions but are not specifically indicative of neuroblastoma. Auscultation revealing wheezing with diminished lung sounds (Choice D) may suggest respiratory conditions rather than neuroblastoma.

Correct Answer: C

Rationale: In this scenario, the 21-year-old mother is showing signs of hemorrhagic shock with increased heart rate, diaphoresis, and vaginal bleeding. The appropriate management includes providing oxygen to support tissue perfusion, treating for shock to restore adequate circulation, and performing uterine massage to help control bleeding during transport. Options A, B, and D do not address the comprehensive management needed for postpartum hemorrhage in this situation.

Correct Answer: D

Rationale: A common clinical manifestation of bacterial meningitis is a positive Kernig sign, which indicates meningeal irritation. Kernig sign is elicited when the leg is bent at the hip and knee at 90-degree angles, and pain and resistance are felt with extension at the knee due to inflamed meninges. Options A, B, and C are not typically associated with bacterial meningitis. A rash is more commonly seen in viral illnesses, photophobia can be present but is not specific to bacterial meningitis, and jaundice is not a typical clinical manifestation of this condition.

Correct Answer: B

Rationale: The correct answer is the sweat chloride test. This test is crucial in diagnosing cystic fibrosis as it measures the amount of chloride in sweat, which is typically elevated in individuals with cystic fibrosis. A chest X-ray (Choice A) may show characteristic findings like hyperinflation or bronchiectasis, but it is not a definitive diagnostic test for cystic fibrosis. Pulmonary function tests (Choice C) may help assess lung function but are not specific for cystic fibrosis. Sputum culture (Choice D) may be used to identify specific pathogens causing respiratory infections but is not a primary diagnostic test for cystic fibrosis.