Answer: The answer is (C) PS is parallel to QR.
Step-by-step explanation: We are given a parallelogram PQRS. The given flowchart shows the sequence of steps in proving that the opposite angles of a parallelogram are equal.
We are to select the missing statement from the flowchart proof.
The conclusion from the missing statement is angle 4 is equal to angle 3.
The reason behind this is that PS is parallel to QR and QS is a transversal, so we have
∠1 ≅ ∠2, since they are alternate interior angles.
Thus, (C) PS is parallel to QR is the correct option.