To determine angle B we need to remember that in a triangle the sum of interior angles is equal to 180°. Then we have that:
[tex]m\angle A+m\angle B+m\angle C=180[/tex]Plugging the values of angles A and C we have that:
[tex]\begin{gathered} 85+m\angle B+11=180 \\ m\angle B=180-85-11 \\ m\angle B=84 \end{gathered}[/tex]Therefore angle B=84° and the asnwer is option B