option vs willing

option and willing both are nouns.

Word	Noun	Adjective	Verb	Adverb
option	Yes	No	No	No
willing	Yes	Yes	No	No

As nouns, willing is a hyponym of option; that is, willing is a word with a more specific, narrower meaning than option:

option (noun)	willing (noun)
the act of choosing or selecting	the act of making a choice
one of a number of things from which only one can be chosen
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

option (adjective)	willing (adjective)
	disposed or inclined toward
	not brought about by coercion or force