It is common to feel abandoned when you are left alone.
The most accurate way to describe the excerpt is to choose the option - it is a dependent clause. This means that something needs to be added - you need to finish the sentence so that it becomes an independent clause, and not a subordinate one.
I would say that all scenarios that are not too complex could be a basis for a short story, but also in principle, you could shorten and simplify any story to make a short story out of it!
So there is no clear distinction.
But among the options, the better candidates are:
a championship basketball game in which a new player is the star
a family mix-up over selecting a birthday present for Dad
the mysterious disappearance of a cake from the pantry
The other options are potentially too complex.
Irony and a metaphor is the best answer to this
