How may novels have been published during the lifetime of William Faulkner

A．prove that foreign experts are important for the U. S.
B．prove visa system used to be more effective in the past
C．show that visa system was not really necessary in the past
D．explain that countries have always been competing for professions

A．the US relies heavily on foreign professionals.
B．visa system may be useless, or even harmful
C．the US government has not put high technology to good use
D．the more efficient the government, the safer the country