I believe the correct answer is D, based on my general knowledge.
Hope I helped. ^ω^
The answer is B.
The Great Migration was the movement of six million African Americans from the Southern U.S. to the North. As you probably know, back in the 1900's, segregation of African Americans was on the rise. At the time, the North was not involved in this segregation, so African Americans migrated to the Northern states to escape discrimination.
The answer is the light bulb.
