The trick here is to remember the definition of a rectangle: a quadrilateral with 4 right angles and 2 sets of equal sides. Using this definition, it means that a square is a technically a rectangle!

Therefore:

QA = 5(5) = 25

QB = 1/2 (5) 10 = 25

QA = QB

However, the above case is simply the maximum possible area of a rectangle with perimeter of 20. Any other rectangle that can be created given a perimeter of 20 will result in an area less than 25.

For example, consider a rectangle with a length of 6 and a width of 4. Such a rectangle satisfies the condition of having a perimeter of 20 but produces a rectangle with an area of 24.

QA = 4(6) = 24 < 25

QA < QB

As the area of a rectangle given a perimeter of 20 could be both equal to or less than 25, we can conclude that for this problem, Answer Choice D is correct.

Hope this helps!