单项选择题

以下选项中不能正确把cl定义成结构体变量的是()

A) typedef struct
   { int red;
    int green;
    int blue;
   } COLOR;
     COLOR cl;
B)struct color cl
   { int red;
   int green;
   int blue;
   }
C) struct color
   { int red;
   int green;
   int blue;
   } cl;
D)struct
   { int red;
   int green;
   int blue;
   } cl;