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 boat having a length 8 m and breadth 2 m is floating on a lake. the boat sinks by 1 cm when a man gets on it. the mass of the man is :
Options: a. 12 kg, b. 60 kg, c. 72 kg, d. 160 kg, e. none of these

Output: d


Input: Consider Input: Problem: in what time will a train 50 m long cross an electric pole, it its speed be 360 km / hr ?
Options: a. 0.25, b. 0.5, c. 1.5, d. 2.5, e. 3.5

Output: b


Input: Consider Input: Problem: a train 700 m long is running at a speed of 78 km / hr. if it crosses a tunnel in 1 min, then the length of the tunnel is ?
Options: a. 288 m, b. 256 m, c. 600 m, d. 278 m, e. 287 m


Output: c