Questions 18 to 20 are based on the following passage. At the end of the passage, you will be given 15 seconds to answer the questions. The "Big Five" refers to ______.
A．weapons, nuclear power, alcohol, gambling and tobacco B．nuclear-power stocks, gambling stocks, liquor stock, tobacco stock and weapons stock C．nuclear-power, gambling, liquor, cloth and food D．weapons company, nuclear power company, gambling company, tobacco company and liquor company