Correct Answer: A

Rationale: Incisors are the teeth that typically erupt first in infants, usually around 6 months of age. These teeth play a crucial role in biting and cutting food. Canines, upper molars, and lower molars are not the primary teeth to erupt in infants. Canines usually erupt after incisors, while molars, whether upper or lower, come in later during the teething process.

Correct Answer: D

Rationale: During crowning, it is essential to apply gentle pressure to the baby's head to prevent rapid delivery, which can lead to potential injuries to both the mother and the baby. Choice A is incorrect because crowning signifies the beginning, not the end, of the second stage of labor. Choice B is incorrect as crowning can occur before or after the amniotic sac ruptures. Choice C is incorrect as transporting the patient during crowning, even if the hospital is close, can be unsafe due to the risk of rapid delivery and complications.

Correct Answer: A

Rationale: After a prolonged hospitalization, a toddler may exhibit excessively demanding behavior as they readjust to being home. This behavior can stem from the child feeling insecure or anxious about the changes in their environment. The child may seek extra attention and reassurance during this transition period. Choices B, C, and D are incorrect because hostility, shallowness in attachment, and withdrawal without emotional ties are less likely behaviors to be displayed by a toddler readjusting to home after a hospital stay.

Correct Answer: D

Rationale: The varicella vaccine is specifically designed to prevent chickenpox. Measles, mumps, and rubella are prevented by different vaccines: Measles is prevented by the measles, mumps, and rubella (MMR) vaccine; Mumps is prevented by the MMR vaccine; and Rubella is also prevented by the MMR vaccine. Therefore, the correct answer is D, Chickenpox, as it is the disease prevented by the varicella vaccine.

Correct Answer: A

Rationale: Monitoring fluid status is crucial for a child with congenital heart disease because these children are at risk of fluid overload, which can exacerbate their condition. Monitoring fluid intake and output helps prevent complications such as heart failure. Encouraging activity may be important, but it should be done cautiously and within limits due to the child's cardiac condition. Promoting a high-calorie diet is not typically a priority in congenital heart disease care unless there are specific indications. Maintaining oxygen therapy may be necessary in some cases but is not the primary intervention for managing congenital heart disease.