I don't see a diagram, but if the portion of the tennis region you are asked to analyze doesn't intersect anywhere else/any other regions pertaining to other sports, wouldn't the sport chosen by these students be solely tennis?
<span>Hola, hablas español?</span>
The formula of an area of a square: 
a - side
We have: 
substitute:

The fromula of a perimeter of a square is: 
substitute:

Option A will be the correct answer