One Way to Understand How Early Environment Influences Differing Behaviors

One way to understand how early environment influences differing behaviors in similar species is through the "cross-fostering" experimental technique.Suppose the curly-whiskered mud rat differs from the bald mud rat in several ways,including being much more aggressive.How would you set up a cross-fostering experiment to determine if environment plays a role in the curly-whiskered mud rat's aggression?

A) You would cross curly-whiskered mud rats and bald mud rats,and hand-rear the offspring to see if any grew up to be aggressive.
B) You would place newborn curly-whiskered mud rats with bald mud rat parents,place newborn bald mud rats with curly-whiskered mud rat parents,and let some mud rats of both species be raised by their own species.Then you would compare the outcomes.
C) You would remove the offspring of curly-whiskered mud rats and bald mud rats from their parents,raise them in the same environment,and then compare the outcomes.
D) You would see if curly-whiskered mud rats bred true for aggression.
E) You would replace normal newborn mud rats with deformed newborn mud rats to see if it triggered an altruistic response.