Using commas to set off nonrestrictive clauses is important for clear writing.
Correctly using commas to set off a nonrestrictive clause is crucial for clarity in writing. In the given options, choice C - 'Nela, who speaks Spanish perfectly, helped us talk to the store owner.' - is an example of a sentence that correctly uses commas to set off a nonrestrictive clause.
https://brainly.com/question/977724