Research Conducted Using the Visual Cliff Has Shown That

Research conducted using the visual cliff has shown that:

A) at nine months of age, babies show no changes in heart rate when placed on either side.
B) at two months of age, babies show accelerated heart rates when placed on the deep side.
C) at two months of age, babies show a drop in heart rate when placed on the deep side.
D) at six months of age, babies show a drop in heart rate when placed on the deep side.