A. struct ord {int x;int y;int z;} struct ord a={1,2,3}; B. struct ord {int x;int y;int z;} struct ord a;a={1,2,3}; C. struct ord {int x;int y;int z;} a={1,2,3}; D. struct {int x;int y;int z;} a;a={1,2,3};