Q: 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: the avg weight of a, b & c is 84 kg. if d joins the group, the avg weight of the group becomes 80 kg. if another man e who weights is 8 kg more than d replaces a, then the avgof b, c, d & e becomes 79 kg. what is the weight of a ?
Options: a. 25, b. 35, c. 75, d. 80, e. 90
A:
d