which sentece has a retrictive clause?

1.Her sister who is a lawyer in New York City ,is coming for the weekend.
2.The book that Mario wrote turned out to be long,dense and boring.
3.Rhode Island,which is the smallest state, is in Northern U.S.
4.The cost of the carpet is $500,which is more than Iwanted to spend.

A restrictive clause?

Restrictive clauses are needed in the sentence for it to make sense. Also, restrictive clauses should NOT have commas before and after them. Most restrictive clauses start with "who" or "which" or one of those pronouns' forms.

Which one do you think it is? I can see it clearly.

??

I think it is 1.

1.Her sister who is a lawyer in New York
City,is coming for the weekend.

No, it's 2. And there should be no commas in that sentence. None!

The sentence that has a restrictive clause is: 2. "The book that Mario wrote turned out to be long, dense, and boring."

To identify a restrictive clause, you need to identify the clause that is essential to the meaning of the sentence and cannot be removed without changing the meaning. In this sentence, the clause "that Mario wrote" restricts the book being referred to. Without this clause, the sentence would simply read, "The book turned out to be long, dense, and boring," which would not specify who wrote the book.

To identify the restrictive clause, you can ask yourself the question: "Which book is being referred to?" The answer to that question is provided by the clause "that Mario wrote," thus making it restrictive.