The correct answer is A) in a cool dry place. The reason for this is that extra chemicals used for producing chemical foam should be stored in a cool, dry place to maintain their effectiveness and prevent degradation. Exposure to excessive heat, moisture, or freezing temperatures can cause the chemicals to break down and lose their fire-fighting properties. Storing the chemicals in a cool, dry location helps preserve their potency and ensures they will perform as intended when used. The other options are incorrect because: B) storing chemicals in open bins would expose them to air and moisture, which can degrade them; C) storing them at a temperature not less than 80°F would subject them to excessive heat, which can also cause deterioration; and D) storing them in a freezer would subject them to freezing temperatures, which is also not recommended for these types of chemicals.