Tea was not only used as a beverage but also for medicinal purposes, paper and printing allowed for record keeping and communication, gunpowder was used as a propellant in firearms and explosives during warfare, and the compass allowed people to navigate on journeys.
The answer is 'B'. Perestroika was a Soviet policy to make the economy more open to foreign competition and individual citizens. Mikhail Gorbachev attempted to reconstruct the economic system of the Communist Party. Example: Ending price controls Glasnost refers to the government becoming more open.