Respuesta :
I'd say that the correct answer is the first one, 'School began on a cold September morning' because it seems the most natural. The last two examples are certainly incorrect, because the comma is placed in the wrong spot. But I am not sure about the second example, although I do think the first one is correct.
Answer:
It would be the first one :3 for sure. the other commas make no sense!!! silly goose this should be easy if you're in highschool!
Explanation: