If the communist and capitalist countries were so different, why had they worked together in WW2?

During the industrial revolution, many governmentsadopted an economic system called capitalism. in thissystem, governments allowed businesses to operate asfreely as possible, capitalism led to economic growth inmany countries and a small number of peoplebecome very wealthy. however the system could be harshfor poor workers, who often worked long hours in unsafeconditions just to make enough money to eat. as a result,some workers turned against capitalism and demandedthat their governments take more control over theireconomies.which statement best describes the passages main idea? a. capitalism was beneficial for some people during the industrialrevolution, but others opposed the system.b. capitalism was mostly a cause of problems during the industrialrevolution, which led to its eventual collapse.c. capitalism became the favored economic system for manycountries during the industrial revolution.d. capitalism was to countries during the industrialrevolution, but became a problem after the revolution ended.edit: correct answer is a