"These countries are also eligible" makes more sense in English and should be accepted. Reporting..
Edit: See my better explanation below. Also, I just thought of a better example for the implied context: "These countries are contenders" This would also apply to winning a contract for example. I feel that while "These countries are possible too" is technically correct English, it's a really bad translation. I think my two examples should also be accepted in the very least.
I wrote my comment as I was doing the lesson off the top of my head.
After looking up the meaning, to me the best translation according to the possible meanings in the following link is the last one: be within the odds.
This sentence is another example of the subtleties of the language and how much information can be conveyed/implied with few words where other languages would struggle with the translation and the resulting sentence would have to be at least twice as long in order to accurately capture the full meaning.
Of course, it being out of context doesn't help and if I had to put it into context I would say that winning at the Olympics, or at least having the potential to win would be the first thing I would think of. In this context, I would say "These countries are the favourites" would be a good translation.
There was a link posted on the duolingo facebook page to an article recently which had a list of Hungarian words that have no equivalent words in English and many other languages. I would put lehetséges into that category.
It may help to break down the word: Lehet means it's possible, lehetség means possibility, and lehetséges in this context should be "with the possibility of...... winning".
favorites are similar in the meaning, but with the possibility of .. means exactly the same. But as I said, to me the olimpics is not a good example, sounds bad, esélyük van/have their chance the thing I would say. Actually the whole contstruction is just on the border of acceptable, not very good. Ezek az országok a lehetséges győztesek, ez az ország egy lehetséges úticél is a better construction (but still l formal).
Well, the Hungarian sentence is what they have decided people should learn therefore the issue here is not with it but the English translation which we both agree has better alternatives. I'd be interested how many people in Hungary who have a good command of the English language would come up with the Hungarian sentence if presented with their English translation first.
Not me and I think almost nobody.
I would say "Ezeknek az országoknak is van lehetőségük" or "Ezek az országok esélyesek" or to form a sentence that is totally different in form like "Ezek az országok is szóba jöhetnek még"-'we can talk about them later' whether they will be good for the purpose we discussed before so there is a chance them to be sufficient.
I think the last is the best because it refers to the most cases, Olimpics and possible journey destination as well.
So glad for the comments saying this was likely sbout possibility to be chosen. At first i thought this was reffering to like catalonia, texas, or other places that may want to be independent. Like they are possible countries becuase they could be formed but haven't been yet.