Please give explanation, thank you!

C) -1

Step-by-step explanation:

For this problem, we simply look at the value f(3) on the graph since it's equivalent to f(c). Once we find the value of f(3), 2, then we find on the graph where 2 is again. We see that at the point (-1,2) this is true. So we can say that C is equal to -1 to make the equation f(c) = f(3).

Cheers.

12 ways

Step-by-step explanation:

one person can get GSB (3)

second person GSB (6)

third person GSB (9)

fourth person GSB (12)