The people who participated in the lecture were related to the military. All of them believed that the UFO really existed, and most people thought that the UFO problem should be studied. Although the lecture held by the National Atomic Experiment Museum was not large, the speakers were very helpful. It can be seen that some very rigorous scientists also believe that UFO really exists. Which of the following, if true, would best support the above argument? ['Some scientists are associated with the military.', 'Some speakers are not rigorous scientists.', 'Some of the participants in the lecture were very rigorous scientists.', 'Scientist lectures are very rigorous and credible.']