Jim Recently Bought a New Bike and Rides It Every

Jim recently bought a new bike and rides it every day, while his old bike sits in the garage untouched. What is Jim's opportunity cost of keeping the old bike?

A) Nothing, since he doesn't really value it anymore
B) Whatever price he could sell the old bike for
C) Whatever price he would be willing to sell the old bike for
D) All of these are correct.