What characterizes a reflex in infants?

A reflex in infants is characterized by an involuntary response to a stimulus, which is why the correct choice emphasizes this aspect. Reflexes are automatic, instinctive reactions that occur without conscious thought. For example, when a baby’s cheek is stroked, they might automatically turn their head towards the touch, seeking out the source. This response is immediate and does not require prior learning or experience, distinguishing reflexes from learned behaviors.

In contrast, intentional actions, emotional responses, and learned behaviors imply a degree of cognitive processing or experience, which does not apply to reflexive actions. Reflexes are crucial during infancy as they play a key role in survival and development, allowing infants to respond to immediate environmental stimuli effectively.