What is being described by this statement “structures and institutions through which decisions are made for a group of people “? asap

How did the completion of the transcontinental railroad change the lives of american citizens? a-it increased the wealth of all americans and enabled them to travel more. b-it made cross-country travel too expensive for ordinary americans. c-it decreased the safety of americans who moved to settle the plains. d-it shortened travel time between the east and west for all americans.

Plz ! after the first battle of bull run general ivan mc dowell was removed from command of the union army he was replaced by a. general ulysses s. grant. b. general george mcclellan. c. general robert e lee. d. general george meade.

What evidence did mary leaky use to understand how early humans thought and felt