Correct Answer: C

Rationale: Gavage feedings are necessary for infants with congenital heart defects to conserve the infant's energy by eliminating the need for sucking. This is important because sucking requires energy expenditure, which can be taxing for infants with cardiac defects. Choice A is incorrect as gavage feedings do not primarily limit the chance of vomiting. Choice B is incorrect because the speed of feeding administration is not the primary reason for using gavage feedings in this case. Choice D is incorrect as the regulation of the quantity of nutritional liquid is not the main purpose of gavage feedings in infants with congenital heart defects.

Correct Answer: B

Rationale: The correct answer is preventing infection. In caring for a child with acute lymphoblastic leukemia (ALL), preventing infection is the priority nursing intervention. Children with ALL are immunocompromised due to the disease and its treatment, making them more susceptible to infections. Administering chemotherapy, while important, is not the priority as preventing infection takes precedence to avoid complications. Monitoring for signs of bleeding and providing nutritional support are also essential components of care for a child with ALL, but preventing infection is the priority to ensure the child's safety and well-being.

Correct Answer: D

Rationale: The classification system of congenital heart defects into acyanotic or cyanotic defects is problematic because children with acyanotic heart defects may develop cyanosis, complicating the differentiation. Cyanosis can occur in some acyanotic defects due to various reasons such as right-to-left shunting or decreased pulmonary blood flow, making the classification based solely on cyanosis misleading. Choice A is incorrect because while the classification may involve hemodynamics, the main issue lies in the potential for acyanotic defects to develop cyanosis. Choice B is incorrect as the ease of identifying children with cyanotic defects does not address the main problem with the classification system. Choice C is also incorrect as the presence of cyanosis is not the only factor determining the classification's validity.

Correct Answer: B

Rationale: The correct answer is B: Steroids. Children receiving steroids should not receive the varicella vaccine as it can increase the risk of severe infection due to the immunosuppressive effects of steroids. Insulin (Choice A), antibiotics (Choice C), and anticonvulsants (Choice D) do not interact with the varicella vaccine in the same way as steroids, and therefore, they are not contraindicated.

Correct Answer: D

Rationale: The correct answer is D: "These responses are replaced by voluntary activity at about five months of age." The grasp reflex and startle reflex (Moro reflex) are normal in newborns but typically disappear as the infant's nervous system matures and voluntary control develops. Choice A is incorrect because checking the responses before deciding a course of action does not address the developmental milestone related to the reflexes. Choice B is incorrect as it jumps to a conclusion of developmental delay without considering the normal developmental process. Choice C is incorrect as additional sensory stimulation is not necessary for the return of these reflexes, as they are expected to naturally diminish as part of normal development.