Answer: a) 1/2, I think
Step-by-step explanation:
Multiply the scale factor for fA (1/8) by the scale factor for fC (4/1).
So, do 1/8 times 4/1 to get 4/8 and then simplify to get 1/2.
I'm not sure if this is how you do it, but this is my bets guess.
