default option vs default

default option and default both are nouns.

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

As nouns, default option and default are synonyms defined as:

default option and default: an option that is selected automatically unless an alternative is specified

default option (noun)	default (noun)
an option that is selected automatically unless an alternative is specified	loss due to not showing up
	an option that is selected automatically unless an alternative is specified
	loss resulting from failure of a debt to be paid
	act of failing to meet a financial obligation

default option (verb)	default (verb)
	fail to pay up