What response is associated with the Moro reflex in infants?

The Moro reflex, also known as the startle reflex, is a key reflex that presents in infants usually during the first few months of life. This reflex occurs when an infant is startled by a sudden stimulus, such as a loud noise or a rapid movement. In response, the infant will typically extend their arms outward, then quickly retract them, as if they are embracing or grabbing for something. This reflex is a vital part of newborn development as it shows the basic neurological functioning of the infant and their reaction to their environments.

The options involving fanning toes, grasping hands, or turning the head toward a touch relate to other reflexes. For example, the toes fanning out when stroked refers to the Babinski reflex, the grasping tightly is linked to the Palmar grasp reflex, and turning the head toward a touch is known as the rooting reflex. Each of these is an important aspect of infant reflexive behavior but distinct from the Moro reflex, which specifically involves a reaction to a loud noise or sudden movement.