20. One analyst predicts that Hong Kong can retain its capitalist ways after it becomes part of mainland China in 1997 as long as a capitalist Hong Kong is useful to China; that a capitalist Hong Kong will be useful to China as long as Hong Kong is prosperous; and that Hong Kong will remain prosperous as long as it retains its capitalist ways.
If the predictions above are correct, which of the following further predictions can logically be derived from them?
(A) If Hong Kong fails to stay prosperous, it will no longer remain part of mainland China.
(B) If Hong Kong retains its capitalist ways until 1997, it will be allowed to do so afterward.
(C) If there is a world economic crisis after 1997, it will not adversely affect the economy of Hong Kong.
(D) Hong Kong will be prosperous after 1997.（B）
(E) The citizens of Hong Kong will have no restrictions placed on them by the government of mainland China.
B怎么推出来的啊？题目并未提到Hong Kong retains its capitalist ways until 1997这一问题啊 | 
