In Formulating a Coffee Blending Problem Where There Are Three $X_{1}, X_{2}$

Multiple Choice

In formulating a coffee blending problem where there are three types of coffee beans, the objective is to find a recipe to make 1 pound of blended coffee that satisfies a set of properties at the least cost. The decision variables are $X_{1}, X_{2}$ , and, $X_{3}$ , representing pounds (actually fractional pounds) of coffee beans used per pound of blended coffee. Suppose that it is required to produce 200 pounds of coffee using this formulation. The appropriate constraint/s, given the definition of the problem and decision variables, will be

A) $X_{1}+X_{2}+X_{3}=200$
B) $200 X_{1}+200 X_{2}+200 X_{3}>200$
C) $200 X_{1}+200 X_{2}+200 X_{3}<200$
D) $X_{1}+X_{2}+X_{3}=1.0$ and multiply the answer by 200 to blend 200 pounds