The constraints of a linear program in standard form are given and graphed together with the objective function line (in dashed lines). Additionally, it is found that point B is optimal. Answer the succeeding questions pertaining to the problem described.

A. Identify points co-optimal with B, if any.

B. Identify degenerate points, if any.

C. Which variables are non-basic at B?

1:x1+x2+s1=02:x1+2x2+s2=93:2x1+x2+s3=12