Explain why C is wrong

Hi @Kanyin, C is incorrect because it does not weaken the argument. If grapefruit juice no longer affects how certain medicines are absorbed only when scientists remove the chemical, then we can safely assume that the majority of, if not all, grapefruit juice sold to the public contains the chemical. Therefore, the conclusion of the argument still holds as the advice provided is sound for anyone consuming grapefruit juice that has not been altered by scientists. Hope this helps! Please let us know if you have any further questions.