to get the answer, lets first make the factors of 12
1 * 12 = 12
2 * 6 = 12
3 * 4 = 12
Now we can easily get our answer, we know
1 +12 =13 so this is not a correct option.
3 + 4 = 7 this is also not the correct answer.
6 + 2 = 8 this is the correct answer
Hope this helped you.. :)