For 9) Joy is correct because a square has four sides so it is always a quadrilateral. Quadrilaterals do not always have equal sides so they are not always squares.
For 10) The answer is C. To be a parallelogram, a shape must have two sets of parallel sides, which all 3 shapes have.
For 11) The answer is A. A square has four sides and four right angles, so it is always a rectangle.
Hope this helped :)