Whatever makes more sense is not necessarily the correct translation, at least not on Duolingo.
With sentences such as 'Die Männer essen eine Erdbeere.', you would assume that it makes more sense for one man to eat a single strawberry, but that's not what the sentence is actually saying. The sentence is indeed saying that multiple men are sharing a single strawberry.
In German, you use sometimes use a different form of ein, depending on both gender and whether you're referring to the subject or object. Einen is used with the object (in this case "apple") only when the object is masculine - neuter objects use ein. However, ein is used for the subject when it is masculine or neuter. For example, "Ein Hund isst einen Hund" (Hund is masculine). Ein Kind isst ein Kind ( Kind is neuter). (Sorry for the graphic examples, but they haven't used many verbs yet, and "to be" is an exception to this rule - there you don't use einen)
It would seem that enough people here have the same opinion that this sentence doesn't make any sense. If it makes sense in German to native speakers, and it is in fact something you would say, then it would in my opinion be better to translate this to comprehensible English. Because regardless of how correct the German is, or isn't, the English phase is something we would never ever say, ever. Ever. It doesn't make any sense at all and this translation is repeated in various forms though out this module.
So what does this sentence really mean in German?