Answer:
A
Step-by-step explanation:
Null means nothing, or zero.
In the case of matrix, a null matrix is a matrix where all its elements are zeros.
They can be of any order, 2 x 3 matrix, 2 x 4 matrix, 2 x 2 matrix etc.
A matrix has a diagonal and other values (non-diagonal). When diagonal is 0 only, and not other, its is still not null. When all the values of a matrix are 0, all the elements are 0, then we call that Null Matrix.
It is equivalent to Zero (0) in the number system.
Correct answer choice is A