Answer:
5.
Step-by-step explanation:
Habituation can be described as a form of learning. In this form of learning, the stimulus becomes less responsive as something occurs in a regular period of time. This form of learning helps to tune out the unnecessary stimuli to help focus on the stimuli that are more important.
This form of learning was used by the researcher Robert Fantz to study infants, in the 1950s and 1960s. In his research, Fantz discovered that infants had this form of learning. An infant reacts less to the repeated presentation than the new ones.
So, the correct answer is option 5.