"Le garçon mange les pommes."
these are hard... have to adjust my ear to le garcon mange vs les garcons mangent
there is clear distinction!! You can hear it from the pronounciation of the article. LE (les) or Leu (le). I can hear it!!
If you want to use the noun without an article in english you usually would use un, une or des. Not le, la, les. They are right for not excepting it without the 'the'
When I took French in school, IIRC I learned that you use the definite article when talking about an object in general. For example, to say I like apples, you would say J'aime les pommes. In this case, Le garcon mange les pommes could mean that the boy eats apples in general, or he could be eating specific apples (THE apples). @SnowboardNW below mentions context, which would help in determining the intended meaning of this sentence.
I wrote that as well, I've sent in a report to let them register our response as correct.
Native English speaker and teacher. The boy eats the apples is not correct. The boy eats apples. The is used as a reference to something specific. The apples would mean... you know, the apples we bought earlier. Since there is no context, the cannot be used.