Why Are Dizygotic Twins Less Likely to Show Concordance for a Monogenic

Multiple Choice

Why are dizygotic twins less likely to show concordance for a monogenic trait than monozygotic twins?

A) Dizygotic twins share fewer allele sequences in common than monozygotic twins.
B) It is possible for dizygotic twins to have different fathers, and monozygotic twins always have the same father.
C) Gene expression in monozygotic twins is less influenced by environmental factors than that of dizygotic twins.
D) Because of their identical appearance, monozygotic twins are more likely to be raised together and share a common environment than are dizygotic twins.