Correct Answer: A

Rationale: The correct dosage to administer 20 mg is 0.4 mL, calculated by dividing the dose (20 mg) by the concentration (100 mg in 2 mL). This calculation ensures the accurate administration of the prescribed medication. Choices B, C, and D are incorrect as they do not reflect the correct calculation based on the provided concentration of the medication.

Correct Answer: A

Rationale: The correct answer is A: Respiratory syncytial virus (RSV). RSV is the most common cause of bronchiolitis, especially in infants. Bronchiolitis is characterized by inflammation of the small airways in the lungs. Choice B, Haemophilus influenzae, is a bacterium that can cause respiratory infections but is not the primary cause of bronchiolitis. Choice C, Parainfluenza, is a common viral infection that can cause croup and other respiratory illnesses but is not the main cause of bronchiolitis. Choice D, Rotavirus, is a virus that primarily affects the gastrointestinal system, causing diarrhea and vomiting, and is not associated with bronchiolitis.

Correct Answer: A

Rationale: The history section of the health record includes details about pregnancy, labor, and delivery, as these factors can have significant implications for the child's health.

Correct Answer: A

Rationale: The correct answer is A, the principle of conservation. Piaget's principle of conservation relates to a child's ability to understand that certain properties of objects remain unchanged despite modifications in their appearance. In this case, the child's understanding that an arm will look the same after the IV is removed demonstrates conservation of appearance. Choice B, transductive reasoning, involves making faulty generalizations based on specific instances and does not apply in this context. Choice C, the principle of identity, pertains to recognizing objects as the same even if they undergo transformations, which is not directly relevant to the scenario. Choice D, reflex abilities, refers to automatic responses to stimuli and is unrelated to the child's understanding of the arm's appearance post-IV removal.

Correct Answer: C

Rationale: During a hospital stay, preschool children may exhibit regression in behaviors such as bed-wetting due to stress. It is important for parents to understand that this behavior is a common response to the hospital environment and should resolve once the child is back home. Therefore, the correct explanation for the nurse to provide to the parents is choice C. Choice A is incorrect because it inaccurately states that the child is no longer potty-trained. Choice B is incorrect as it assumes a medical issue without evidence. Choice D is incorrect as it dismisses the parents' concerns without addressing the underlying cause of the behavior.