Respuesta :
The sentence using the correct capitalization is the third:
"The Red Cross is a liaison for the families of soldiers stationed in other countries, acting as a go-between for separated spouses, parents and children."
Neither liaison nor soldiers need to be capitalized, since they are only common nouns, while the Red Cross is the proper noun of an institution and as such, it needs to have each word capitalized.
The Red Cross is a proper name, so it has to be caitalized, whereas the words soldiers and liaison are common nouns and in this case shouldn´t be iniciated with upper case. Therefore the correct alternatice is: The Red Cross is a liaison for the families o soldiers staitioned in other countries, acting as a go-between for separeted spouses, parents and children.