Testing Infants of Different Ages with the Visual Cliff Apparatus

Testing infants of different ages with the visual cliff apparatus has found that

A) six- to seven-month-old infants perceive drop-offs but do not fear them.
B) two-month-old infants perceive drop-offs but do not fear them.
C) six-month-old infants show no response to the deep side of the cliff.
D) both two- and six-month-old infants will crawl across the shallow side of the cliff but will cry when enticed to crawl over the deep side of the cliff.