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: 54671 - 14456 - 31466 = ?
Options: a. 2449, b. 5449, c. 8749, d. 8449, e. 6468
c

Problem: at what price must an article costing rs. 47.50 be marked in order that after deducting 7 % from the list price. it may be sold at a profit of 25 % on the cost price ?
Options: a. 63.84, b. 62.6, c. 62.1, d. 62.7, e. 62.2
a

Problem: what is the area of an equilateral triangle whose one side length is 50 ?
Options: a. 225 √ 3, b. 325 √ 3, c. 425 √ 3, d. 525 √ 3, e. 625 √ 3

e