The correct answer is he information gathered is reliable because it came from a government website.
When searching for information online we should always do a background check of the entity providing the information. In the case of scientific knowledge, the information published on the websites of reputable sources, like scientific institutes, governmental institutions and research facilities that provide full insight into their data, methodology and sources is the one we should trust. In this case, Stefan is obtaining data from a big database constructed by an international team of experts in genetics that has been revised and approved by the scientific community.