The correct answer is D. along.
A line can be drawn along the page in many different ways. For example, you could draw a straight line from the top left corner of the page to the bottom right corner. Or, you could draw a curved line that goes around the edge of the page. You could also draw multiple lines that intersect each other in different ways.
The other options are not correct because they do not describe how to draw a line along the page. Option A, on, means that the line should be drawn on top of the page. Option B, across, means that the line should be drawn from one side of the page to the other. Option C, above, means that the line should be drawn above the page.
I hope this explanation is helpful. Please let me know if you have any other questions.