Answer :

Shummy
You are correct #8 is the highest number.
First, I will list the factors of 80
80:
1, 2, 4, 5, 8,10,16, 20, 40, 80

Now the factors of 116:
1, 2, 4,19,58, 116

Therefore, your answer is 4. Since their highest common factor is 4