Option
“1 An act of choosing : exercise of the power of choice.
2 The power or right to choose (as between alternatives) : freedom of choice.
3 Something that is offered for choice or that is chosen: ELECTIVE
Synonyms; see CHOICE”
“Involving or depending on the exercise of an option : left to the discretion of the one concerned : not compulsory or obligate.”
Source: Webster’s Third International Dictionary