B and 3 are linked.

As long as they meet the requirements, they get RAF experience:
a) Accounts directly RAF linked; and
b) Characters grouped together; and
c) Characters within +/- 4 levels of each other; and
d) Characters at level 79 or lower; and
e) Mob or Quest is not grey to either character

Similarly, your 1 & 2 will get RAF, even if "A" is level 90 and "1" is the same level as 12B3...