Start by naming any country that France borders. Then name any country that borders any of those countries. Then keep going until there are no more countries left to name.
It's true that Serbian, Croatian, and Bosnian are mostly considered as one language by name Serbo-Croatian, because they are mutually intelligible. But standard variety of this language in Croatia is called both officially and commonly "Hrvatski" (in english "Croatian). So the better answer would be "Hrvatski".