Solve the following goal programming model graphically and then answer the multiple choice questions that follow.minimize P$1$d$1*,$ P$2$d$2$; Pdsubject to:$4$x$1+2$x$2+$ d$1-$ d$1*=80$x$1+$ d$2-$ d$2=30$x$2+$ d$3-$ d$3*=50$x;$,$ di$,$ d; $=0$For the solution to this problem, da is equal to$?$