Ounces, a chemical manufacturing company, wants to build a number of storage buildings for the 6 hazardous chemicals it produces. The company could build a separate storage building for each chemical, but that would be very costly. Instead, they store some chemicals in the same building, following the guidelines of the federal safety regulations summarized in the table below. Here the chemicals are labeled A through F, and a "No" indicates that the pair of chemicals in that row and column cannot be stored together.

a. Draw a graph that models this situation.
(You can use the letter to the right, or design your own)
F
b. In this graph the vertices represent
c. In this graph, 2 vertices are connected by an edge if
d. Use your graph to determine the least number of storage buildings the plant must build. Explain how you arrived at your answer and why it is the minimum number required.
The minimum number of storage buildings is
• I determined this by ...