i think that the statement is justified, as a square has a equal length for each of its sides, and qualifies the requirements to be a rhombus. but a rhombus might not fulfill the requirements to be a square, like the requirement that all sides of the figure must be parallel in order to be a square.
i think that all of the answers are correct, as a trapezoid is indeed a four sided figure with only one set of parallel lines, while Squares and parallelograms are quadrilaterals as both have 4 sides each, and the opposite sides of a square and parallelogram are parallel, because as far as they go on, they will never meet.
No. I do not agree with this statement as not all of the different types of parallelograms have equal length in each side, therefore it does not fufill the requirement to be a square