In the diagram, \triangle{QUR} and \triangle{SUR} are equilateral triangles. Also, \triangle{QUP},\triangle{PUT} and \triangle{TUS} are isosceles triangles with PU=QU=SU=TU and QP=PT=TS. The measure of \angle{UST}, in degrees, is
Answer Choices
A. 50
B. 54
C. 60
D. 70
E. 80