By the late 1940s, the united states produced of all the economic output in the world.

The correct answer is:  One half.  What revived the US economy after the Depression in the early 1940s was expending of the war. During World War II the United States' economy grew by about 10 percent a year. More Americans were able to buy houses after the Second World War because people were more willing to go into debt.

d) all choices are correct