Which situation is modeled by the equation below?
100 + (-100) = 0
A. winning $100 in a contest, then paying a $100 electric bill
B. winning $100 in a contest, then donating half of it to a charity
C. paying $100 for a video game system, then paying $100 more for video games
D. paying $100 for a video game system, then selling it to someone else for $200