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.

Input: Consider Input: Problem: what is the value of n if the sum of the consecutive odd intergers y from 1 to n equals 169 ?
Options: a. 47, b. 25, c. 37, d. 33, e. 29

Output: b


Input: Consider Input: Problem: a train traveling at 72 kmph crosses a platform in 33 seconds and a man standing on the platform in 18 seconds. what is the length of the platform in meters ?
Options: a. 240 meters, b. 360 meters, c. 420 meters, d. 300 meters, e. can not be determined

Output: d


Input: Consider Input: Problem: in what time will a train 200 m long cross an electric pole, it its speed be 144 km / hr ?
Options: a. 2.5 sec, b. 1.9 sec, c. 8.9 sec, d. 6.9 sec, e. 5 sec


Output: e