Which of the following graphs represents a function with a domain of [0, ∞) and a range of [0, ∞)?

Domain is how far to the left and right the line goes on the x axis
range is how far up and down the line goes on the y axis

we see both go from 0 to infinity
the domain from 0 to infinity means that the line has to be only on the right side of the origin

the range from 0 to infinity means the line has to be above the origin

combine those to get in quadrant I

that would be the 3rd graph