Tea made from camellia leaves is a popular beverage. However, studies show that regular drinkers of camellia tea usually suffer withdrawal symptoms if they discontinue drinking the tea. Furthermore, regular drinkers of camellia tea are more likely than people in general to develop kidney damage. Regular consumption of this tea, ttherefore, can result in a heightened risk of kidney damage. Which one of the following, if true, most seriously weakens the argument? ['Many people who regularly consume camellia tea also regularly consume other beverages suspected of causing kidney damage.', 'Most people who regularly drink camellia tea do not develop kidney damage.', 'Addictive chemicals are unlikely to cause kidney damage solely by virtue of their addictive qualities.', 'Several other popular beverages contain the same addictive chemical that is found in camellia tea.']