The Nurse in a Pediatric Clinic Is Performing Well-Baby Checks

The nurse in a pediatric clinic is performing well-baby checks. The nurse is checking an infant who is 7 months old for developmental milestones. Which finding is of greatest concern to the nurse?

A) The infant remains flat when in a supine position.
B) The infant exhibits a Babinski reflex.
C) The infant opens and closes her hands to grasp objects.
D) The infant exhibits a lack of startle reflex to sound.