Is "Elegir" used only for voting?! Like, choosing a president. But not a pair of jeans.
What are you saying, when choosing jeans?!
Or! ... Is it about "final" choosing between two or three last "candidates" of jeans? :)
But, anyway, how you say "choose", while looking through hundreds of jeans?!
If you were marked wrong, it was just one of Duo's flukes. Probably happens every day somewhere on Duo, but only rarely to one individual. But be aware that they also might have shown you a different accepted answer which might have made you think there was a different sort of problem.