A, C, & E
A point has the coordinates of (x,y). The x coordinate being along the horizontal line and y coordinate being along the vertical line. So, first, we have to identify the coordinates.
A: (3,0)
B: (0,3)
C: (3,1)
D: (1,3)
E: (3,5)
F: (5,3)
As you can see, A, C, and E have the x-coordinate of 3.
Hope this helps!
Let me know if you need anything else :)