Which one do I write first?

For the remaining classes of my fiction writing course, we have to write about 3 short stories. Last time, we did an exercise to come up with 3 story ideas and one is preferably the first short story we turn in. I plan to do these three, but I don't know which one to do first.

One was completely BS-ed at the last minute of a germaphobe witnessing someone on a bus get sick from pneumonia and get rushed to a hospital. It came from a weird dream I had a while back.

The second is a mixed and matched story of my latest medical adventures. I honestly can't think of anything else at the moment.

The third is something like a guy letting a secret crush slip through his fingers when she ends up going with someone else because he never had the courage to say anything. The professor doesn't mind if it's romance as long as it's well written and that it's not sci fi or fantasy.

I can choose another one, but these are the only ones I've got.

We can only write them fresh, so I can't exactly do them all and wait until they're due. I'd rather leave the best one for last so I can have my best skills for the moment to write it in. If I have one that has great potential, I'd rather write it with skill. any and all suggestions would be great, thanks!