When the hand is holding the $6\mathrm{.}0-lb$ stone, the humerus $H,$ assumed to be smooth, exerts normal forces $F_C$ and $F_A$ on the radius $C$ and ulna $A,$ respectively, as shown.

Part A

If the smallest cross$-$sectional area of the ligament at $B$ is $0\mathrm{.}30i{n}^2,$ determine the greatest average tensile stress to which it is subjected.

Express your answer in pounds per square inch to three significant figures.