In order to realize her dream of returning to her slim figure in the past, Mrs. Wu, who was getting fatter and taller, started to use French Martha diet pills. She took them strictly in accordance with the instructions for use of the medicine and did not dare to slack off. Still not alleviated. Visible, French Mansa diet pills are completely ineffective? Which of the following, if true, would most weaken the above conclusion? ['Mrs. Wu will be fatter if you use French Mantha diet pills.', 'French Mansa diet pill has obtained the health food approval certificate of the Ministry of Health of China.', 'French Mansa slimming pill sales top three similar weight-loss products for three consecutive years.', 'French Mansa diet pills are more expensive than domestic diet pills.']