Correct Answer: B

Rationale: Hypotonic dehydration occurs when the loss of electrolytes exceeds the loss of water, leading to a decrease in plasma osmolarity. This often occurs when sodium loss is greater than water loss, as in diarrhea or vomiting.

Correct Answer: A

Rationale: Sudden and severe scrotal pain in an adolescent male is a medical emergency and may indicate testicular torsion, which requires immediate evaluation and intervention to prevent testicular loss.

Correct Answer: A

Rationale: Hypernatremia typically presents with lethargy, oliguria, and intense thirst due to the body's attempt to conserve water. Apathy can also occur, but lethargy and thirst are more consistent indicators.

Correct Answer: A

Rationale: Hydrocarbon poisons include substances like gasoline, turpentine, and lighter fluid, which are typically liquids derived from petroleum. Bleach is a corrosive substance, not a hydrocarbon.

Correct Answer: B

Rationale: The NCHS growth charts serve as reference guides for all racial or ethnic groups, including African American children. The 20th percentile for height and weight does not indicate nutritional failure but provides a reference point for ongoing assessment. Choice A is incorrect because being at the 20th percentile does not automatically imply the need for nutritional intervention. Choice C is incorrect as there is no correction factor specifically used for nonwhite ethnic groups in this context. Choice D is incorrect as a single measurement at the 20th percentile can provide valuable information for assessment.