The tension in the left-hand string in terms of _{1}, _{2}, and m is
A) mg cos _{1} / (sin _{1} sin _{2} + cos _{1} cos _{2 })
B) mg sin _{2} / (sin _{1} sin _{2} + cos _{1} cos _{2 })
C) mg cos _{2} / (sin _{1} sin _{2} + cos _{1} cos _{2 })
D) mg cos _{2} / (sin _{1} cos _{2} + cos _{1} sin _{2 })
E) mg cos _{2} / (sin _{1} cos _{2} + cos _{1} sin _{2 })