Answer:
Step-by-step explanation:
the was I understand matrix multiplication, I re-learned tonight so I could be wrong but.....
according to Gaggle matrix multiplication is possible when the number of columns in matrix 1 equals the number of rows in matrix 2
it is called the dot product (that sounds familiar)
first choice has 2 columns and 1 row can't multiple this one
second choice has 1 column and 2 rows can't multiple this one
third choice has 2 columns and 1 row can't multiple this one
fourth choice has 1 column and 1 row This one can be multiplied
