hello!
2 is a factor of all even numbers (numbers that end with 2, 4, 6, 8, 0)
Option A) is wrong because 1, 3, 5, 7, 9 & numbers that end with the digits listed above are not evenly divisible by 2; this is the reason why Option C) is wrong.
In order for a digit/number to be a factor of a number, it should be evenly divisible by that number.
note:-
Hope everything is clear; if you need any more explanation/clarification, kindly let me know, and I will comment and/or edit my answer. :)