Estimates of Heritability Made by Comparing Related Individuals Assume That

Estimates of heritability made by comparing related individuals assume that the environments of related individuals:

A) are more similar than those in which unrelated individuals are raised.
B) are not any more similar than those in which unrelated individuals are raised.
C) are manipulated so that some sibs within each family experience either one of the extreme ends of the environmental range.
D) have no effect at all on phenotypic variance in the family.
E) are identical for every sib in the family.