Which Statement Best Summarizes the Results of Research Studies Regarding

Which statement best summarizes the results of research studies regarding depth perception using the visual cliff apparatus?

A) Infants who are 2 months old will show a change in heart rate when placed on the deep side of the cliff.
B) Infants show no response to the deep side of the cliff until they are 4 months old.
C) Infants who are 6 months old are willing to cross the deep side of the cliff.
D) Infants show no response to the deep side of the cliff until they are nearly 1 year old.