Which of the statements about the y-axis are true?

I. The y-axis is a vertical number line that passes through the origin.
II. The y-axis intersects the x-axis at the point (0 , 0).
III. The y-axis is the first coordinate in an ordered pair that describes the vertical distance from the origin.
IV. The y-axis is a horizontal number line that passes through the origin.
I only
II and IV
IV only
I and II