which is the correct option

Two round bars are wolded together and loaded axially as shown. If $d_1=2in,d_2=1\mathrm{.}5in.,P_1=20$

kip $,$ and $P_2=10$kip, determine the tensile stress at the middle of AB portion of the bar.

$9\mathrm{.}55$ ksi

$12\mathrm{.}6$ ksi

$22\mathrm{.}4$ ksi

$8\mathrm{.}50$ ksi