If heredity is an important determinant of a specific behaviour, what prediction can we make about expression of the behaviour in identical twins reared apart compared to its expression in fraternal twins reared apart?

• A. Fraternal twins will express the behaviour more similarly than identical twins.
• B. There will be little similarity in the expression of the behaviour in either set of twins.
• C. Identical twins will express the behaviour more similarly than fraternal twins.
• D. The behaviour will be expressed as similarly by identical twins as it is by fraternal twins.