The Sizes of Two Matrices a and B Are Given $4 \times 4$

Multiple Choice

The sizes of two matrices A and B are given. Find the sizes of the product AB and the product BA, if the products are
defined.
-A is $4 \times 4$ , B is $4 \times 4$ .

A) $\mathrm { AB }$ is $8 \times 4$ , BA is $8 \times 4$ .
B) $\mathrm { AB }$ is $4 \times 4$ , BA is $4 \times 4$ .
C) $\mathrm { AB }$ is $4 \times 8$ , BA is $4 \times 8$ .
D) $\mathrm { AB }$ is $1 \times 1$ , BA is $1 \times 1$ .