Use the Following Information to Answer the Question(s) Below -When a Model Has a Unique Optimal Solution, It Means

Use the following information to answer the question(s) below.
Cerebro Manufacturing produces four types of structural support fittings-plugs, rails, rivets, and clips-which are machined on two CNC machining centers. The machining centers have a capacity of 250,000 minutes per year. The gross margin per unit and machining requirements are shown in the spreadsheet below. $\begin{array}{|l|l|l|l|l|l|l|}\hline&{\text { A }} & \text { B } & \text { C } & \text { D } & \text { E } & \text { F } \\\hline& \text { Cerebro } && & & & \\1&\text { ManufacturingModel } & & & & & \\\hline 2\\\hline 3 & \text { Product } & \text { Plugs } & \text { Rails } & \text { Rivets } & \text { Clips }& \begin{array}{l}\text { Machine } \\\text { Capacity } \\\text { (mins./year) }\end{array} \\\hline 4 & \text { Gross margin/unit } & \$ 0.40 & \$ 1.20 & \$ 0.80 & \$ 1.10 & \\\hline 5 & \text { Minutes/unit } & 1 & 2 & 3 & 1.5 & 250,000 \\\hline 6 & \text { Gross margin/minute } & \\\hline 7 & \text { Maximum production } & \\\hline 8 & \text { Profit } & \\\hline\end{array}$
-When a model has a unique optimal solution, it means that .

A) the objective is maximized or minimized by more than one combination of decision variables
B) there is no solution that simultaneously satisfies all the constraints
C) the Allowable Increase or Allowable Decrease values for changing cells are zero
D) there is exactly one solution that will result in the maximum or minimum objective