Your Book Described a Study of Severely Deprived Children from Romanian

Your book described a study of severely deprived children from Romanian orphanages who were adopted before age two into homes in the United Kingdom. The children were able to make substantial improvements, but the longer they experienced the deprived environment the more severe their cognitive impairments remained four to six years later. These data suggest

A) the value of longitudinal studies for demonstrative cognitive skills
B) the existence of critical periods for human development
C) that humans have sensitive periods for intellectual development
D) the importance of moral reasoning skills for cognitive development