Suppose the diagonals of a parallelogram are both perpendicular and congruent. Which type of special quadrilateral is it? Use the most descriptive name possible.

A. rhombus

B. rectangle

C. square

D. parallelogram

C. Square

For the angles to be perpendicular they must be at 90°, which means the shape must have a right angle, which eliminates rhombus and parallelogram. Square is congruent because the angles and lengths are all the same.