Mensa IQ riddle - lines inside circles

I think you want more from this "riddle" that it actually is. First of all the goal of this puzzle is to evaluate your ability to see patterns. To do that it's enough for one answer to fit better that all the rest. And this is what F does.

It doesn't have to be ideal both:
1. because it's a test-like question, you have discrete amount of options
2. because all patterns in the real life are approximate and it may test your ability to find patterns despite their distortions.

If you wish one can formulate the relation A->B and C->F like this:

1. Rotatate around 180 degree.
2. Duplucate amount of bars in each group.
3. Shift each group arbitrary by any angle in between -30 and 30 degree

I think the procedure is like so:

1. Visit every group of bars
2. For each group, replicate it and add it clockwise from the original group
3. Rotate the whole circle by 180 degrees

You could probably swap steps 2 and 3, but I find it harder to understand that way.

Try "folding" them in half, and duplicating there. They're just exactly opposite and duplicated.

I.E. The bottom left of b is 12 because the 4+2(6) duplicates are overlapping at that point in the circle. Top of b is 18 as the duplicates of both 3 and 6 (9).

As I'm trying to edit this and clean it up I realize I think I misunderstood your question... But why does it have to be clockwise/counterclockwise? If you duplicate outward from the midpoint of each set, maybe that helps clarify?