The following network diagram represents a minimum cost transshipment problem.

Assume that X_IJ is represents the quantity shipped from node I to node J.

Which of the following statements are true for this problem?

Group of answer choices

a) This problem has a feasible solution when the requirement at node D is increased by 15.

b) At the optimal solution, the constraint at node B will be binding.

c) Each decision variable appears in exactly 2 of the constraints in this problem's formulation, excluding non-negativity constraints.

d) At the optimal solution, the constraint at node A will be binding.

e) Exactly two of the answers are correct.

10 15 $10 B D $8 $7 $5 $3 -80 A $3 $7 $6 $9 C E $5 30 15