Answer:
The activity that exhibits a potential trade-off with enrolling in rock climbing is:
reading piano sheet music.
Step-by-step explanation:
A potential trade-off with enrolling in rock climbing that Megan faces is the next available course, which is the reading of piano sheet music. She can either enroll in the rock climbing or the reading of piano sheet music. When she chooses one course, the other course will be left unchosen. This can be likened to opportunity cost. But strictly, a trade-off involves all forgone alternatives, while an opportunity cost involves the best alternative.