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: the telephone company wants to add an area code composed of 2 letters to every phone number. in order to do so, the company chose a special sign language containing 524 different signs. if the company used 522 of the signs fully and two remained unused, how many additional area codes can be created if the company uses all 524 signs ?
Options: a. 46, b. 248, c. 2092, d. 15,128, e. 30,256
Output:
c