[单选题]
Three vectors, expresse,ha1p u sf9a)td:bx me3h6k-w36 l) ;fbp 95rvjpjqz vv in Cartesian coordinates, are S = (-3.5,+4.5) T = (0,-6.5) U = (+5.5,-2.5) What is the angle of the resultant vector S + T + U measured from the positive x axis?
A. $24^{\circ}$ above
B. $24^{\circ}$ below
C. $66^{\circ}$ above
D. $66^{\circ}$ below
