Insomnia or poor sleep quality can seriously affect people's physical and mental health. The survey found that many people with poor sleep have the habit of drinking coffee before going to bed. Therefore, drinking coffee can help improve sleep quality. It is an auxiliary means for treating insomnia. Which of the following is true and the conclusion to the question is the most powerful refutation? ['Coffee has a good sleeping effect.', 'There is evidence that coffee has a refreshing effect, which is likely to cause them to sleep poorly.', 'Coffee is a favorite drink.', 'Coffee aids in the treatment of insomnia, will have serious side effects.']