To multiply a 2x3 matrix, we must multiply it by which of the following:
a. the number of columns in the first matrix must match the number of rows in the second matrix.
b. the number of rows in the first matrix must match the number of rows in the second matrix.
c. the number of columns in first matrix must match the number of columns in second matrix.
d. the number of rows in first matrix must match the number of columns in second matrix.
