Answer:

B. Rectangle

Step-by-step explanation:

Rectangle as we all know it is a parallelogram with equal measures of opposite sides. We also know that all its angles are right angles or 90 degrees so that means if yoy draw any diagonal on any of the vertices, we can get the value of this diagonal by getting the hypotenuse of a right triangle formed by the line with height and base measuring equally to the length and width of the rectangle. Thus, on any occasions as long as the dimensions of the rectangle is not changed or modified, the diagonal of a rectangle will have a single value. its diagonals will always be congruent.