You will be given a definition of a task first, then some input of the task.
Given a math problem with context and a question and 5 answer choices, the task is to provide the correct answer choice based on the problem. You must choose one of the given answer choices by letter: a, b, c, d, or e; anything else is invalid.

Problem: 3 sets of 40, 50 and 60 students appeared for an examination and the pass percentage was 100, 90 and 80 respectively. the pass percentage of the whole set is
Options: a. 88.33, b. 84.33, c. 88.66, d. 84.66, e. none of these
Output:
c