One of a set of choices that can be made.
The freedom or right to choose.
A contract giving the holder the right to buy or sell an asset at a set strike price; can apply to financial market transactions, or to ordinary transactions for tangible assets such as a residence or automobile.
To purchase an option on something.
The new novel was optioned by the film studio, but they'll probably never decide to make a movie from it.
To configure, by setting an option.