Question

Which quadrilateral will always have 4-fold reflectional symmetry

Answer 1

I believe it's the square. The square can be divided into four equal parts, each able to reflect each other. 

Answer 2

Square

Square can be folded in half:

- over the vertical line

-over the horizontal line

-over either diagonal (2 diagonals)

So the square has 4 lines of symetry

Rectangle  2 lines

Trapezoid  1 line

Parallelogram   no lines