Which of the following is NOT a property of pyrethrin described in the material?

• A. It kills fleas quickly
• B. It is biodegradable
• C. It does not build up in the bloodstream
• D. It permanently colors the dog's coat

Answer: (D)

The main idea here is understanding how pyrethrin is described to behave in topical flea-control products. Pyrethrin is a natural insecticide that acts quickly to kill fleas, so rapid flea kill is a described property. It is also described as biodegradable, meaning it breaks down rather than persisting in the environment. When used as directed on a dog, it doesn’t accumulate in the bloodstream, so there’s no long-term systemic buildup. It is not a dye or coloring agent, and there’s no description of it permanently coloring a dog's coat. So the statement about permanently coloring the coat isn’t a property of pyrethrin described in the material.