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.

[EX Q]: 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
[EX A]: a

[EX Q]: Problem: find value for x from below equation ? x + 1 = - 3
Options: a. 1, b. - 4, c. - 1, d. 2, e. 3
[EX A]: b

[EX Q]: Problem: the area of a square garden is a square feet and the perimeter is p feet. if a = 2 p + 26.25, what is the perimeter of the garden, in feet ?
Options: a. 28, b. 36, c. 40, d. 42, e. 64
[EX A]:
d