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: bob wants to run a mile in the same time as his sister. if bob ’ s time for a mile is currently 11 minutes 20 seconds and his sister ’ s time is currently 9 minutes 36 seconds, by what percent does bob need to improve his time in order run a mile in the same time as his sister ?
Options: a. 3 %, b. 5 %, c. 8 %, d. 10 %, e. 15 %
[EX A]: e

[EX Q]: Problem: what least number must be added to 696, so that the sum is completely divisible by 20 ?
Options: a. 2, b. 4, c. 3, d. 5, e. 6
[EX A]:
b