Abstract Principle?

In the question, they define "abstract principle" in contrast to a decision made by calculated self-interest or the desire to adhere to societal norms or conventions. A, B, C, and E are all clearly made because of either self-interest or the desire to adhere to norms. D, on the other hand, is justified because Jadine believes the environment is more important than money. This is an abstract principle because it's not based on self interest or adhering to norms, unlike the other options.