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 sum of money at simple interest amounts to rs. 720 after 2 years and to rs. 1020 after a further period of 5 years. the sum is :
Options: a. 400, b. 500, c. 600, d. 700, e. 800
[EX A]: c

[EX Q]: Problem: an investor deposited $ 10,000 to open a new savings account that earned 12 percent annual interest, compounded quarterly. if there were no other transactions in the account, what was the amount of money in the account 6 months after the account was opened ?
Options: a. $ 10,300, b. $ 10,303, c. $ 10,600, d. $ 10,609, e. $ 10,900
[EX A]: d

[EX Q]: Problem: find the smallest number which should be multiplied with 560 to make it a perfect square.
Options: a. 60, b. 55, c. 45, d. 25, e. 35
[EX A]:
e