The Correct answer is C.

Explanation

The marked angles in the figure are angles P, Q, R, and S, which are the angles of a quadrilateral, and angles T, U?, and V, which are the angles of a triangle. The sum of the degree measures of the angles of a quadrilateral is 360, and the sum of the degree measures of the angles of a triangle is 180. Therefore, the sum of the degree measures of the marked angles is 360??plus 180, which is 540.