The summer rains and bad weather in Europe in the early 14th century resulted in a famine. The weather made the crops fail and people depended on those crops to eat, without them they would starve. The correct answer is A.
The Progressive Era is a period of "widespread" social activism and political reform across the United States that spanned from the 1890s to the 1920s. The main objectives of the Progressive movement were eliminating problems caused by industrialization, urbanization, immigration, and corruption in government.
Because that's how a civilization starts and strives. They make permanent or semi-permanent houses near bodies of water in order to grow crops, wash clothing, and they also probably started making homes with the mud.
Hopefully I explained it well :]
Gold in California was accidentally found by prospectors when news of this golden land reach to the rest of the colonies they decide to mine there.