A possible one.
A possible choice, notably someone being considered for a position.
Jones is a possible for the new opening in sales.
A particular event that may happen.
(usually not comparable) Able but not certain to happen; neither inevitable nor impossible.
It's not just possible, it's probable.
Capable of being done or achieved; feasible.
It's possible for anyone to learn to pay the bagpipes.
Being considered, e.g. for a position.
Jones and Smith are both possible for the opening in sales.
Apparently valid, likely, plausible.