On the flipside, I wrote "Do you prefer the rice or the bread?" and it was marked as incorrect. I interpreted this as though someone were asking someone which they liked better in a particular instance (e.g. "do you prefer the rice or the bread Sue made?) rather than in general. I think it should be marked correct.
Apparently it is acceptable to use the definite article (in translating to English) on both of the nouns, or omit it completely. But it is not correct to use it only on one noun, i.e., Do you prefer the rice or bread? is incorrect. It has to be 'the rice or the bread' or 'rice or bread.'
This is what it would sound like at a native speed because, as in many languages, words tend to blend together when there are many vowels that are next to each other such as in this case "il risO O Il pane." The sentence would sounded jerky and stunted if you pronounced it clearly!