2. After 2 days working at a day-care center, Roman no longer snaps to attention every time a child screams.

The change in Roman’s behavior is most likely due to habituation. Sally, who has only been working at the center for 2 hours, still exhibits an orienting reflex every time a child screams. In a study examining the effects of time spent around children on habituation of one’s orienting reflex to children’s screams, what would be the independent variable?

a. Orienting reflexes

b. Habituation

c. The screaming children

d. Time spent around children