Consider Debbie's Nursery problem again:

Debbie's Nursery grows indoor flowers. Two of her top$-$selling flowers are Night$-$delight and Morning$-$shine. Nightdelights earn a profit of $$25$ per unit and Morning$-$shines earn $$18$ per unit. Two major resources are utilized in the growing process of both: topsoil and labor time. It takes $8$ pounds of topsoil to grow a Night$-$delight, and $5$ pounds to grow a Morning$-$shine. Each Night$-$delight requires $4$ hours of labor; each Morning$-$shine requires $1$ hour. For the current growing season, $5000$ pounds of topsoil and $1500$ hours of labor are available.

Noting the decision variable for Night$-$delight with letter $N$ and for Morning$-$shine with letter $M,$ which of the followings represents the best identification of all the constraints for the problem?