Describe the economic and social event that influenced the rise of imperialism in the mid- 1800’s

In the Age of New Imperialism that began in the 1870s, European states established vast empires mainly in Africa, but also in Asia and the Middle East. ... European nations pursued an aggressive expansion policy that was motivated by economic needs that were created by the Industrial Revolution.

D. George Washington was appointed as the commander of the Continental Army.

Explanation:

The Second Continental Congress met in May of 1775.  Representatives from all thirteen colonies were there.  Though they did not want to break away from Britain yet, they were well aware that it would possibly come to that and that they needed to be ready in case war broke out.  The Congress decided to create it's own army to be prepared and decided to name George Washington as the commander of the Continental Army.