Problem
Select the correct choice that completes the sentence below. You are asked to find $A B$, the product of two matrices. If $A$ is an $m \times n$ matrix and $B$ is o $\times p$ matrix, you can multiply $A B$ if and only if
Solution
Step 1 ：The multiplication of two matrices is only possible when the number of columns in the first matrix is equal to the number of rows in the second matrix. In this case, if A is an m x n matrix and B is an o x p matrix, the multiplication AB is possible if and only if n equals o.
Step 2 ：Final Answer: \(\boxed{n = o}\)
