I believe the answer is A: the first satellite launched into space.
Answer:
A secondary source summarizes large amounts of evidence.
Explanation:
Primary sources correspond to “primary literature” and are those that present themselves and are disseminated exactly as they are produced by their authors. Primary sources are original materials on which other research is based. This type of source presents the information in its original form, without interpretation, summarization or evaluation by other writers.
On the other hand, secondary sources are interpretations and evaluations of primary sources for this reason present a series of evidences that support their interpretations. In this sense, secondary sources may be more useful than a primary source.
Answer:
O A. A central government was formed
