Recall that the equation of a line in slope-intercept form is given by

Where m is the slope and b is the y-intercept of the line.
The y-intercept is the point where the line intersects the y-axis.
From the graph, we can see that the line intersects the y-axis at y = -3
So, the y-intercept is -3
The slope of the line is given by

The rise is the vertical distance between the two points on the line.
The run is the horizontal distance between the two points on the line.
So, the equation of the line is

Therefore, option A is the correct answer.