What was the time frame of the progressive era

The Progressive Era (1896–1916) was a period of widespread social activism and political reform across the United States that spanned the 1890s to the 1920s. The main objectives of the Progressive movement were addressing problems caused by industrialization, urbanization, immigration, and political corruption.

Explanation:

I looked it up

a and c?

i think it is a and c

option d is correct. corroborated sources of historical evidence   is necessary to validate a claim about an event in history.

historians tend to use written sources, but audio and visual materials as well as artifacts are important objects that supply information to modern historians.

historical sources are usually divided into two categories: primary and secondary sources. depending on the historian's intent, some sources shift their designation. determining what type of sources toimplement, and the level of credibility and reliability of those sources, is a significant step in critical thinking for the historian.

explanation: