# List Product / Combinations With Strings

I have a list like this in Mathematica:

list1 = {{"A"},{"B","C"}}


I am trying to output a second list that has the combinations of these elements but while maintaining the order, i.e., A should come first:

list2 = {{"A","B"},{"A","C"}}


But, I am not sure how to do this efficiently.

Thanks.

You can use Distribute:

Distribute[list1, List]


{{"A", "B"}, {"A", "C"}}

Tuples @ list1


{{"A", "B"}, {"A", "C"}}