To find the distance between two points, the formula would be
d = square root[(x1-x2)^2 + (y1 - y2)^2]
Let's assign point 1 to be P1(1,2) and point 2 to be P2(4,6). Then
d = square root[(1-4)^2 + (2 - 6)^2]
d = square root (25)
d = 5 units
The answer is either A or B. They are just the same :)