Which of these quadrilateral types must have congruent diagonals. a. rectangle, square, rhombus b. square, rhombus c. rectangle, square d. parallelogram, rectangle, square, rhombus

( C. Rectangles and squares)
This is because a square IS a rectangle and has alike properties. A rectangle always has congruent diagonals,therefore passing the property onto the square. Even though a square is a combination of a rhombus, a rhombus doesn’t have congruent diagonals. Finally, a parallelogram can be any shape so it doesn’t necessarily have to have congruent diagonals

21/2 or 5/2