A nurse is reinforcing teaching about infant car seat use with a group of new parents. Which of the following instructions should the nurse include in the teaching?

A. "You should place a folded blanket to pad the back of the infant's head.": Adding extra padding behind the infant’s head is not recommended because it can interfere with the harness system and reduce the effectiveness of the car seat in a crash. B. "You should position the car seat at a 30-degree angle.": The recommended angle for a rear-facing car seat is 45 degrees to help keep the infant’s airway open. A 30-degree angle may allow the head to fall forward, risking airway obstruction. C. "You should use a car seat with a four-point harness.": The safest infant car seats use a five-point harness, which provides better restraint at the shoulders, hips, and between the legs to distribute crash forces more effectively. D. "You should place the retainer clip at the level of the infant's armpits.": The chest clip should be positioned at armpit level to ensure the harness straps remain in place over the shoulders and reduce the risk of injury in the event of a collision.