Answer:
Answer Choice 2
Explanation:
Since there are multiple inputs that give a SINGLE output, this is considered a function. This is not to be confused with a single input, that could give multiple outputs (for example on the left side there would be 2 5's that correspond to a 10 or a 6 on the right side of the chart)
The Domain is the left side of the chart, and the range is the right side which only has 1 output (4)
I hope this helps, this can be a bit confusing, so if you need more help just comment and I'll be happy to help you.