Which of the Following Is TRUE with Regard to Sources

Multiple Choice

Which of the following is TRUE with regard to sources of variability?

A) The chromosomes in the zygote are not exact copies of those in the mother's ovaries and the father's testes.
B) Fraternal twins develop from a single zygote that splits into two genetically identical replicas.
C) For each genotype,only a single corresponding phenotype can be expressed.
D) Identical twins develop from separate eggs and separate sperm.