please help with this math quiz

Answer:
C
Step-by-step explanation:
The domain of a function is shown on a graph by all the values on the x-axis. Basically, the domain is wherever the function goes through a coordinate containing an x value.
Here, the graph starts at -6 on the x- axis and ends at 6 on the x - axis. Every number between them has a x-coordinate, making the domain of that function every number between -6 and 6.