default vs default option

default and default option both are nouns.

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

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

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

default (noun)	default option (noun)
loss due to not showing up	an option that is selected automatically unless an alternative is specified
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 (verb)	default option (verb)
fail to pay up