For some time now,world leaders _______ out the necessity fo

For some time now,world leaders _______ out the necessity for agreement on arms reduction.
A.had been pointing B.have been pointing
C.were pointing D.pointed

.[答案]B
[译文]一段时间以来,世界首脑都一直指出有必要就裁军问题达成共识.
[答案解析]从该句中的时间状语for some time now可以看出,主句的动作从过去某一时间开始一直持续到现在,而且动作可能还会延续,故应该用现在完成进行时.