correct answer will get brainliest and full ratings.

Hope this helps but I think the answer is A.To find this look at the points on the graph and find out what their ordered pairs are. Once you do that look at the x values for all the ordered pairs.Example the x value for the ordered pair (-3,-1) is -3.After you have found all the x values put them in order from least to greatest.I any x values are repeated then leave them out.Example if your x values are 0,1,1,2,3,3,4 then leave the extra 1 and 3 out and then you have 0,1,2,3,4.Once you have put the x values in order from least to greatest  and left out any extra repeated x values the you are done and you have your domain for the function.