单项选择题

对二维数组的正确定义是()

A.int a[ ] [ ]={1,2,3,4,5,6};
B.int a[2] [ ]={1,2,3,4,5,6};
C.int a[ ] [3]={1,2,3,4,5,6};
D.int a[2,3]={1,2,3,4,5,6};