Which property makes a rectangle a special type of parallelogram?

a. the opposite angles are congruent.
b. the diagonals are congruent.
c. the opposite sides are parallel.
d. the consecutive sides are congruent.

Option 'B' is correct.

Step-by-step explanation:

Since we know that

Properties of rectangle are:

1) Opposite angles are equal and right angles too.

2) Opposite sides are equal, so they can be equal.

3) Diagonals are congruent and bisect each other at right angle.

Properties of parallelogram are:

1) Opposite sides are parallel.

2) Opposite angles are equal.

So, Only if the diagonals are congruent , then it makes a rectangle a special type of parallelogram.

Hence, Option 'B' is correct.