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: a goods train runs at the speed of 72 kmph and crosses a 250 m long platform in 24 seconds. what is the length of the goods train ?
Options: a. 230 m, b. 240 m, c. 260 m, d. 270 m, e. none of these

Output: a

Input: Consider Input: Problem: a and b started a business investing rs. 80,000 and rs 20,000 respectively. in what ratio the profit earned after 2 years be divided between a and b respectively ?
Options: a. 4: 1, b. 3: 2, c. 18: 20, d. 18: 4, e. 17: 4

Output: a

Input: Consider Input: Problem: the length of the bridge, which a train 140 metres long and travelling at 45 km / hr can cross in 30 seconds, is ?
Options: a. 255, b. 267, c. 235, d. 277, e. 211
Output: c