A number of possibilities (beyond the obvious, which is that they actually happened that way).
I had done my duty not only as a writer, but also a mathematician: exhausted all possibilities.
The possibilities are as endless as the programming here at WPNQ!
late 14c., "condition of being possible," from Old French possibilité (13c.) and directly from Latin possibilitatem (nom. possibilitas) "possibility," from possibilis (see possible (adj.)). Meaning "a possible thing or substance" is from c.1400. Related: Possibilities.