If Monozygotic Twins Reared Together Are More Alike on a Characteristic

If monozygotic twins reared together are more alike on a characteristic than monozygotic twins reared apart, what can you infer regarding the relative roles of heredity and environment in determining that characteristic?

A) Heredity plays a role.
B) Environment plays a role.
C) Heredity plays no role.
D) Environment plays no role.