Lines PS,QT and RU intersect at a common point O, as shown. P is joined to Q,R to S, and T to U, to form triangles. The value of \angle P+\angle Q+\angle R+\angle S+\angle T+\angle U is
Answer Choices
A. 450^\circ
B. 270^\circ
C. 360^\circ
D. 540^\circ
E. 720^\circ