Goal Programming Solution Feedback Indicates That the D₄⁺ level of 50

Goal programming solution feedback indicates that the d₄⁺ level of 50 should not be exceeded in future solution iterations.How should you modify your goal constraint to accommodate this requirement?
40 X₁ + 20 X₂ + d₄^? + d₄⁺ = 300

A) $\text { Increase the RHS value from } 300 \text { to } 350 \text {. }$
B) $\text { Replace the constraint with } 40 \mathrm{X}_{1}+20 \mathrm{X}_{2} \leq 350$
C) $\text { Do not modify the constraint, add a constraint } \mathrm{d}_{4}^{+} \leq 50$
D) $\text { Do not modify the constraint, add a constraint } d_{4}+=50$