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: 10 ^ ( 600 ) ã · 10 ^ ( 580 ) = ?
Options: a. 10 ^ 10, b. 10 ^ 20, c. 10 ^ 22, d. 10 ^ 23, e. 10 ^ 24
[EX A]: b

[EX Q]: Problem: a batsman makes a score of 87 runs in the 17 th inning and thus increases his average by 3. find his average after 17 th inning.
Options: a. 39, b. 88, c. 26, d. 87, e. 11
[EX A]: a

[EX Q]: Problem: find the smallest number which should be multiplied with 36963 to make it a perfect square.
Options: a. 4, b. 7, c. 4, d. 3, e. 6
[EX A]:
d