Remark
The only points that can lie on the y axis are a and d. There has to be a zero someplace. But the question is where?
The answer is in the graph below. (0,6) is in red and it is on the y axis.
(6,0) is blue and is on the x axis.
So if you want a point to lie on the y axis, the answer is that the x part of the point must be 0.
Answer D
