It's c. 7.
Think of all the different ways you could get a 7: 1 and 6, 2 and 5, 3 and 4. To get 10 you need 5 and 5 or 4 and 6. To get nine you need 6 and 3 or 5 and 4. To get 4 you need 3 and 1 or 2 and 2. To get 2 you need 1 and 1.
See how you have a higher chance of getting the 7?
