Quadrilateral pqrs is inscribed in a circle, as shown. which statement is true? a) the measure of ∠p is equal to the measure of arc qrs, and the measure of ∠r is equal to the measure of arc spq, so angles p and r are supplementary. b) the measure of ∠p is equal to the measure of arc qrs, and the measure of ∠r is equal to the measure of arc spq, so angles p and r are complementary. c) the measure of ∠p is equal to half the measure of arc qrs, and the measure of ∠r is equal to half the measure of arc spq, so angles p and r are supplementary. d) the measure of ∠p is equal to half the measure of arc qrs, and the measure of ∠r is equal to half the measure of arc spq, so angles p and r are complementary.