CD is a line segment and let M be the mid-point of the line segment.
As we know that a mid-point divides the line in two equal parts, this means that the length of line segment will be the double of distance between one end and mid-point
The answer in this question is B The diagonals of the parallelogram are congruent because that's only possible for right angle quadrilaterals. We can say that the diagonals of the parallelogram are congruent. The diagonals of this figures have the same size and shape.