You will be given a definition of a task first, then some input of the task.
In this task, you are given a multiple-choice question about healthcare. Answer the question based on your information and classify your answers into '1', '2', '3', and '4'.

Question: In order to check the efficacy of a treatment to stop smoking, a control group (placebo) is compared with a treated group. For groups to be comparable it is important that they do not differ much in the age of the participants. We are informed that the average age in the control group is 52 years and that in the treated group it is also 52 years. From this information we can say that:
Options: <1> The groups do not differ with respect to the distribution of the age variable. <2> If the study is well designed, it can not give us the same average age in both groups. <3> To compare the distribution of the age variable in both groups, it would be convenient to know a measure of dispersion as the standard deviation in addition to the mean. <4> For the final conclusion it does not matter the distribution of age in both groups, only if the treatment is effective or not. <5> If, in addition to the mean, the median and the fashion agree, we can affirm that the groups do not differ with respect to the distribution of the age variable.
Output:
3