Which two statements are true for a two-dimensional array?

A.
All methods of the class Object may be invoked on the two-dimensional array.

B.
It is implemented as an array of the specified element type.

C.
Using a row by column convention, each row of a two-dimensional array must be of
the same size.

D.
At declaration time, the number of elements of the array in each dimension must be
specified.