Quadrilateral OPQR is inscribed in circle N, as shown below. Which of the following could be used to calculate the measure of ∠PQR?


(6x − 4)° + (2x + 16)° = 180°
(x + 16)° + (6x − 4)° = 180°
(6x − 4)° + (2x + 16)° = 360°
(x + 16)° + (6x − 4)° = 360°