In equilateral triangle PQR,S is the midpoint of PR,T is on PQ so that PT=1 and TQ=3. Many circles can be drawn inside quadrilateral QRST so that no part extends outside of QRST. The radius of the largest such circle is closest to
Answer Choices
A. 1.00
B. 1.10
C. 1.15
D. 1.05
E. 1.37