Rolling four standard dice, what is the probability that the product of the four results is even?

Rolling four standard dice, what is the probability that the product of the four results is even?

 

I kind-of dont understand this problem

 

4!= 24

so there are 24 possible combinations

the only factor that makes the product odd is 4 odds (O x O x O x O)

so shouldn't the answer be 23/24?