The traditional view is that high egg yolk cholesterol content is directly responsible for hypertension, atherosclerosis, coronary heart disease and stroke. Therefore, many middle-aged and elderly people are afraid to eat egg yolk. Recently, nutritionists have organized a special study The panel on the relationship between egg yolk and cholesterol conducted a six-month experiment on 116 men aged 50 to 65 years. Assume the following are the results of several experiments. Which will weaken the traditional view the most? ['Divided the subjects into two groups and ate egg yolk and egg white, respectively.', 'Divided the subjects into two groups and consumed egg yolk and egg white, respectively.', 'The subjects were divided into two groups, one group consumed egg yolk and one group did not consume egg yolk. After six months, it was found that the cholesterol content of the subjects who did not consume egg yolk was reduced.', 'The subjects were divided into two groups, one group ate egg yolks and one group ate no egg yolks. The cholesterol content of the subjects did not change after half a year.']