Need what had the greatest impact on pre-historic man, causing them to revert back to a nomadic lifestyle? a. tribal warfare b. changes in climate c. introduction of the horse d. larger populations

Option 'B' = changes in climate, had the greatest impact on pre-historic man.

Changes on the weather forced men to move periodically or cyclically, usually returning to their original location at various times. When they moved to colder climates, they would make clothing out of animal skins, to protect themselves. When the nomads learned  how to plant, they didn't need to search for other places anymore.

The answer is option B.

Explanation:

Changes on the climate constrained men to move occasionally or consistently, typically coming back to their unique area at different occasions. When they moved to colder atmospheres, they would make dress out of creature skins, to secure themselves. At the point when the travelers learned  how to plant, they didn't have to look for different places any longer.

b. major john c. frémont led a rebellion called the bear flag revolt.

explanation:

during the bear flag revolt, from june to july 1846, a small group of american settlers in california rebelled against the mexican government and proclaimed california an independent republic. the republic was short-lived because soon after the bear flag was raised, the u.s. military began occupying california, which went on to join the union in 1850. the bear flag became the official state flag in 1911.