How do you negate C?

Hi Tyler, This is a tough one to negate- lets try an attempt, but also try a different approach. I try to replace an unless with an "even if," that is, an LP can recommend an herb even if that herb is not offered for sale as a drug" Another approach would be to try to treat this as a must be true question. If we can show that the author must hold this opinion (if their argument is to make sense), then it is the correct answer. This is the same thing as negation, but without having to go through with negating each answer choice.