You will be given a definition of a task first, then some input of the task.
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: a rectangular grassy plot 110 m. by 65 m has a gravel path 2.5 m wide all round it on the inside. find the cost of gravelling the path at 40 paise per sq. metre
Options: a. s 340, b. s 780, c. s 880, d. s 480, e. s 980
Output:
a