The following conditional statement is true. A quadrilateral has four right angles if it is a square. Which of the following statements must also be true?
a) If a quadrilateral is not a square, then it does not have four right angles.
b) If a quadrilateral does not have four right angles, then it is not a square.
c) If a quadrilateral is a square, then it does not have four right angles.
d) If a quadrilateral has four right angles, then it is a square. None of the above