Problem: William was responsible with energy consumption, but Steven was wasteful for the reason that

My choice: William was environmentally responsible.

Problem: Jason drove in a car to their workplace while Kyle biked, so

My choice: Kyle often wore a helmet on their way to work.

Problem: Developing marketing campaigns came easy for Emily but not Carrie because

My choice: Carrie had insufficient experience.

Problem: Bugs freak Sarah out, while Katrina is a lover of them

My choice:
Sarah is an indoor human being.