Apoint is represented by a single dot and

a- a lowercase letter
b- an uppercase letter
c- naming two points on a line
d- an uppercase script letter

The most possible answer is B- an uppercase letter because a point is pointed towards the highest elevation and back to the lowest elevation making the highest elevation an uppercase and the lowest elevation an uppercase. For example, lowest elevation would be B whilst highest elevation is H. That would make it (A,H). Unless you were doing a negative point but nobody uses those these days.

Hope this helps. :)