Given function for remaining amount of money over $2500 earnings E(x) = x-2500.
And function for total commission earn C(x) = 0.02x.
We need to find the composite function that would use to calculate your commission earned if you sold $6000.
The composite function that would use to calculate your commission earned would be : C of E(x).
That is C(E(x)) = (C o E)(x) = 0.02(x-2500).
Now, in order to calculate the commission earned if you sold $6000, we need to plug x=6000 in (C o E)(x) = 0.02(x-2500) composite function.
(C o E)(x) would become (C o E)(6000).
Therefore, correct option is first option (C o E)(6000).