Rmember that the form y = mx + b is a straight line whose y-intercept is b and slope is m.
On the graph you can see that the y-intercept is beteween 0 and 5.
The equations given as options have y-intercepts 6, 20, 18, and 3, in that order.
And the only equation of the options that meet that is the option D. y = 3x + 3.
You can also check that the slope of that equation is 3 and it is roughly the slope of an intermediate line between the dots.
Answer: option D. y = 3x + 3.
