How might one support the statement that the development of major depressive disorder has moderate genetic contributions?
A. The co-twin of a monozygotic twin with major depressive disorder is twice as likely to develop the condition as are dizygotic co-twins.
B. The co-twin of a dizygotic twin with major depressive disorder is twice as likely to develop the condition as are monozygotic co-twins.
C. Two parents with depression are no more likely to have children with depression than parents without depression.
D. Depression in one parent (and not the other) can actually serve as a protective function against depression in their children.