Answer:
The correct answer is A. The shape formed by the four chairs is a square.
Explanation:
A square is a figure whose 4 sides are exactly equal in length, and whose 4 interior angles are equal to 90 degrees each. Thus, if the distance between the chairs is exactly the same between them, it is understood that the "sides" of the figure are all the same. Thus, if all the internal angles of the figure are 90º, the figure that the chairs form is a square.