What does a fine future behind them (line 3 of paragraph 3) means? .

A.Some people will certainly have a promising future though they are not very competent in their present work.

B.Some people don’t have any potential for their work though they are employed.

C.Some people can have a bright future though they can’t

D.their work well.

D.Some people have potential when they are employed, but never realize that potential.

正确答案：D