Final answer:
The sentence uses allusion by referring to the character Scrooge from 'A Christmas Carol' to describe Sue's frugal use of money.
Step-by-step explanation:
The sentence "Sue acts like Scrooge with her money and will not buy anything if she does not need it" demonstrates the use of allusion as a figure of language.
Allusion is a reference to a well-known person, place, event, literary work, or work of art, used to make a comparison in the readers' minds. In this case, the character Scrooge from Charles Dickens' "A Christmas Carol" is referenced, a character known for his miserliness.
This allusion helps the reader understand Sue's character as someone who is extremely tight with money.