To purchase an option on something.
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.
One of a set of choices that can be made.
The freedom or right to choose.
The acquiring or retention of a nationality through personal choice as a right, bypassing selective legal mechanisms for naturalization, especially in cases where a territory is transferred or passed on from one state to another.