option

(n) the right to buy or sell property at an agreed price; the right is purchased and if it is not exercised by a stated date the money is forfeited
(n) one of a number of things from which only one can be chosen
- what option did I have?
- there no other alternative
- my only choice is to refuse
alternative, choice,
(n) the act of choosing or selecting
- your choice of colors was unfortunate
- you can take your pick
selection, choice, pick,

alternative choice selection pick

optic

optics

optional optionally