#1. Lila shares a house with two other people. She is a concert pianist and often practices at home. One roommate enjoys listening to her practice, but the other does not. For the roommate who enjoys...

#1. Lila shares a house with two other people. She is a concert pianist and often practices at home. One roommate enjoys listening to her practice, but the other does not. For the roommate who enjoys listening to Lila play, this is an example of ________; for the other roommate, it is an example of ________. a. the tragedy of the commons; the third-party problem b. a positive externality; a negative externality c. a positive externality; the free-rider problem d. the free-rider problem; the tragedy of the commons e. a negative externality; the tragedy of the commons