Answer:
Its D you have a pfp that makes sense it's hard
Plurilingualism is a situation wherein a person who has competence in more than one language can switch between languages from one language to another and vice versa
"between the two countries"
A prepositional phrase needs to contain a preposition, in this case it would be "between". As well it needs to modify the sentence and it should mention the object of the sentence. So "between the two countries" is correct.
Any answer choices?to pick from