Small punctuation question

Hi,

Sorry.  Not grammar, but punctuation.

Which is correct?

1. Which do you prefer?  Coffee or tea.

2. Which do you prefer?  Coffee or tea?

3. Which do you prefer: coffee or tea?

Of these choices, I'd choose #3. However, I'd rather say Which do you prefer, coffee or tea? 

Best wishes, Clive

Hi,

If the list is longer, can you still use commas?

Can you say this:

Which do you like best, coffee, tea, orange juice or water? You can say it, but you have to use your judgement about when the list gets too long and awkward. Then you could use a colon, although you could also just express it another way depending on the context.

eg I have coffee, tea, orange juice and water. Which do you like best?

You don't always have to restrict yourself to one sentence.

Best wishes, Clive