Answer:
Explanation:
The marginal benefit of eating the 3rd sandwich is the amount in which Kyra benefits improve with this action.
If Kyra has already eaten two sandwiches she has some benefits, let it be B. If she eats a 3rd sandwich she will have another aggregate level.of benefit, let it be B'.
As the marignal benefit is how her benefit variates with the 3rd sandwich it will be B' - B. It is, the difference between the benefit of eating 3 and 2 sandwiches.
Correct option: A