答案及解析：[单选题]For art gallery problem of n-gon without holes, which statement is right? 关于不带孔洞的n边多边形的画廊问题来说，下列哪个论述

问题：

[单选题]For art gallery problem of n-gon without holes, which statement is right?
关于不带孔洞的n边多边形的画廊问题来说，下列哪个论述是正确的？
An/3 guards are insufficient (n/3个哨兵可能是不够的)
Bn/3 guards are always sufficient (n/3个哨兵总是足够的)
CAt most n/3 guards are needed (至多需要n/3个哨兵)
DAt least n/3 guards are needed (至少需要n/3个哨兵)