Le/la/l'/les are called definite articles; they correspond to 'the' in English but are used more often in French. Your quiz requires that all country names start with such a definite article, which is understandable as they appear most of the time (though not always) before country names, but this can be confusing as they are not part of the noun itself and so if you require them you should at least mention it in the quiz description.
And perhaps more importantly, Haiti belongs to a small group of Country names that never have an article, so "le Haiti" is always wrong.
-The flag of France is the wrong way
-How were we supposed to know the article was necessary?
-In what way are these countries (still) French? Especially Rwanda, which was never part of France?
And perhaps more importantly, Haiti belongs to a small group of Country names that never have an article, so "le Haiti" is always wrong.