My son brought home a review sheet from math today and there is one question on it that I can't seem to answer! So, who can tell me the correct answer and why? Here's the question:

A rectangle is

*never*a ________.

a.) parallelogram

b.) square

c.) rhombus

d.) quadrilateral

e.) polygon

My thinking is that a rectangle is, sometimes, all of these things. Am I missing something here? :???: