Superconductors are substances that conduct electricity without resistance at low temperatures. Their use, however, will never be economically feasible, unless there is a substance that superconducts at a temperature above minus 148 degrees Celsius. If there is such a substance, that substance must be an alloy of niobium and germanium. Unfortunately, such alloys superconduct at temperatures no higher than minus 160 degrees Celsius. If the statements above are true, which one of the following must also be true? ['The use of superconductors will never be economically feasible.', 'The use of superconductors could be economically feasible if there is a substance that superconducts at temperatures below minus 148 degrees Celsius.', 'No use of alloys of niobium and germanium will ever be economically feasible.', 'Alloys of niobium and germanium do not superconduct at temperatures below minus 160 degrees Celsius.']