In an independent-measures design, we investigated the effect of a new fitness program on participants' cardiovascular endurance. 24 Participants were randomly assigned to two groups: Group A (16 participants) and Group B (8 participants). The participants in Group A followed the new fitness program for 8 weeks, while the participants in Group B did not participate in any fitness program. At the end of the 8 weeks, we measured the cardiovascular endurance of all participants. What was the purpose of randomly assigning participants to two groups in this study?
1) To ensure that the participants in each group were similar in terms of their cardiovascular endurance
2) To eliminate the influence of individual differences on the results
3) To determine the effectiveness of the new fitness program on cardiovascular endurance
4) To compare the cardiovascular endurance of the participants in Group A and Group B
