Which of these is not an allusion? select all the apply

a brief or indirect reference to a well-known person, character, or event
a brief or indirect reference to a well-known person, character, or event

a struggle between two opposing forces
a struggle between two opposing forces

a comparison between two otherwise unlike objects, people, or places
a comparison between two otherwise unlike objects, people, or places

the literal definition of a word

The option "the literal definition of a word" is not an allusion.