Look at the line carefully. You can see that the line crosses the point (0,2). See it? The value of 2 in the point (0,2) is the y-intercept.
The given equations are all in the form
y = mx + b, where b is the y-intercept.
So, based on this data, we conclude that the line represents the equation y = (1/3)x + 2.
Choice C is the answer.