3) is one of the primary scientific techniques for obtaining information about people without a written history.

Letters, diaries, speeches, and photographs are examples of primary sources. Artifacts such as tools are also primary sources.

Explanation:

Other tools that historians use are secondary sources. They are written after a historical event by people who did not see the event.

Some serfs would run away to live in a town because they no longer wanted to be a serf and have to do all the hard labor while other people higher up in the caste ladder got to live much fuller and richer lives just because they were born into the right families