Goal programming solution feedback indicates that the $d{4}^{+}$level of $50$ should not be exceeded in future solution iterations. How should the goal constraint be modified to accommodate this requirement?

$40x1+20x2+d{4}^{-}+d{4}^{+}=300$

Do not modify the constraint; add the constraint $d{4}^{+}50.$

Replace the constraint with $40x1+20x2350.$

Increase the RHS value from $300$ to $350.$

Do not modify the constraint; add the constraint $d^{+}=50.$