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: what is the units digit of 26 ! + 50 ! + 4 ! + 4 ! ?
Options: a. 8, b. 6, c. 4, d. 2, e. 0
[EX A]: a

[EX Q]: Problem: if the ratio of two number is 6: 7 and lcm of the number is 450 then what is the number.
Options: a. 11, b. 20, c. 25, d. 30, e. 35
[EX A]: a

[EX Q]: Problem: a no. when divided by 221 gives a remainder 43, what remainder will beobtained by dividingthe same no. 17 ?
Options: a. 3, b. 6, c. 9, d. 10, e. 12
[EX A]:
c