Delores repeatedly showed curtis, her two-month-old, a picture of his grandfather. she noticed that curtis seemed to become less interested in looking at the picture each time she showed it to him. then she showed curtis a picture of his grandmother, and he looked at it as long as he had first looked at his grandfather's picture. curtis's loss of interest in his grandfather's picture demonstrates a) continued response b) operant response c) recovery from habituation d) habituation of attention.

d) habituation of attention          

Explanation:

Habituation of attention: One of the forms of learning, in which a person gets habituation from a piece of information after being encountered repeatedly that no longer the information bothers the person's consciousness.

This is what exactly has happened in the case of Curtis, that he loses interest in his grandfather's picture after the repeated exposure to it.

The phenomenon explains that there is a declination or decrements in the occurrence of a particular behavior after getting a repeated exposure to a given stimulus that causes the behavior.

if im not mistaken its a. collective emotional arousal