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.
--------
Question: Problem: the perimeter of an isosceles right triangle is 12 + 12 sq rt 2. what is the length of the hypotenuse of the triangle ?
Options: ['a. 5', 'b. 6', 'c. 7', 'd. 8.485', 'e. 8']

Answer: d

Question: Problem: evaluate: 98612 / 22 * 11 * 70 = ?
Options: a. 700.4, b. 704.4, c. 740.4, d. 744.4, e. 700.0

Answer: b

Question: 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

Answer:
d