Answer: C
Explanation:
Domain is all of the x values in a set of coordinate pairs.
Set: {(4, 9), (-6, 1), (-2, 5), (3, 1))
Step 1: Find every x coordinate
*In every ordered pair like the above, each set of coordinates is given in the order x, then y). So X comes first in every coordinate pair (or set of 2 coordinates)
X values: 4, -6, -2, 3
Step 2: Put into brackets
{4, -6, -2, 3}
This is the domain in order. Putting it in a different order won't change anything as long as they are the same numbers.
Answer= C
Hope this helps!! :D