Which sentence is punctuated correctly?

Question

anonymous · Answer

Be careful David, or you'll slip on the ice.
Be careful, David or you'll slip on the ice.
Be careful, David, or you'll slip on the ice.
Be careful David or you'll slip, on the ice.

anonymous · Answer

c because David is not needed in this sentence

anonymous · Answer

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anonymous · Answer

will u help me with my question

anonymous · Answer

I think that the answer is A, not C. Try reading both sentences, pausing at the commas. C almost sounds like a threat, foreshadowing that the speaker is going to make David slip on the ice if he does something the speaker doesn't like. Sorry, I have a wandering mind. Anyways...yeah..look for smooth sentence flow versus choppy sentence flow. Good luck!