If points A and B are (6-1) units apart, which of the following can have only one possible value?
I. The area of a square region with side AB
II. The circumference of a circle passing through points A and B
III. The area of a rectangular region with diagonal AB  Choose the correct choice from the following:  A) I only  B) II only  C) III only  D) I and II only  E) I and III only
I. The area of a square region with side AB --&gt; side=AB=(6-1) or 5 --&gt; the area of a square is 5^2=25, so only one possible value;   II. The circumference of a circle passing through points A and B --&gt; circle is not defined by only two points, hence the circumference of a circle passing through points A and B can take infinitely many values. For example consider when AB=diameter and when points A and B are not the endpoints of the diameter;   III. The area of a rectangular region with diagonal AB --&gt; consider the case when AB is the diagonal of a square (the area is 25/2) and the case when AB is the diagonal of a rectangle with the sides equal to 3 and 4 (the area 12).   I onlynswer: I only.
<result>A</result>
If points A and B are (6-1) units apart, which of the following can have only one possible value?
I. The area of a square region with side AB
II. The circumference of a circle passing through points A and B
III. The area of a rectangular region with diagonal AB