Comparing two items: How does 「...と...とどちらが」work?

Question

I've seen the pattern 「...と...とどちらが」when comparing two items, but I'm unclear how it works. Here's an example: 肉と魚とどちらが好きですか。"Which do you prefer, meat or fish?"

I'm unclear what the second と after 魚 is doing. I know you can include a と after BOTH items when you're listing two items with "and", but then it seems like that 「肉と魚と」 is just floating in space. Since this is a standard polite sentence and not a casual conversational one, it seems like some other particle like は, or even just a comma (indicating an omitted は) should be there.

Or, is that second と supposed to be the "target of comparison" と, the same one used in ...と同じ or ...と違う?

What's the grammar breakdown of this common phrasing, especially for the second と?

Answer 1

According to デジタル大辞泉, it is not the と meaning and (格助詞), but a particle of another category 並列助詞. It is a marker for enumeration.

［並助］いくつかの事柄を列挙する意を表す。「君―ぼく―の仲」 「幸ひの、なき―ある―は」〈源・玉鬘〉

Note that weblio lists it as a 格助詞 and 並列 is a usage. So the category is a matter of opinions.

Either way, both と are more like commas and different from と in と同じ/違う.