D4. Consider the following linear program: Minimize 8x1 + 10x2 + 9x3 Subject to: -2x1 + -4x2 + 6x3 _ 25 X1, X2, 23 2 0 Call C1 the dual constraint associated with x1, C2 the dual constraint associated with 2, and C3 the dual constraint associated with 3, and let y denote the dual variable. Which of the following is true? The optimal dual solution is y = 1 O. C1 is binding at optimality. O C2 is binding at optimality. O C3 is binding at optimality