What does the signal word "Caution" on a pesticide label indicate about the toxicity of the product?

A pesticide with the signal word "Caution" is considered to be the least toxic among all the options given. This means that if used according to instructions, the product is unlikely to cause harm to humans or the environment. The other options are incorrect because "Moderately toxic", "Not toxic at all", and "Very toxic" all indicate varying levels of toxicity, with "Very toxic" being the highest level of toxicity.