What is indicated by the Moro reflex?

The Moro reflex, also known as the startle reflex, is a reaction that occurs in infants when they suddenly feel like they are falling or are startled by a loud noise. This reflex involves a distinctive movement pattern where the infant spreads their arms out to the sides (abduction) and then brings them back in towards the body (adduction), often resembling the shape of a "C" with their fingers. This response is an instinctive reaction aimed at grasping onto something for support. Therefore, indicating that the index finger and thumb come together to form a "C" is a clear representation of what happens during the Moro reflex.

Other options do not accurately depict the Moro reflex. The flexing of the arms and legs, the jerking movement of the leg, and the turning of the head to a sound involve different reflexes or muscle responses not associated with the startle response indicated by the Moro reflex.