Which of the following groups of words in bold is nonrestrictive and should therefore be set off with commas in the sentence?

A.My yarn which is blue and gray will make a very pretty scarf.
B.Hats knitted by my mother are worn all winter by my family.
C.The person who taught her to knit is my great-aunt.
In "A" its which is blue and gray
In "B" its knitted by my mother
In "C" its who taught her to knit
I think it's B...?

"Non-restrictive" means basically that the phrase or clause is not necessary to the meaning of the sentence. Therefore, I would go with option A.

Thank you

You're correct! In Sentence B, "Hats knitted by my mother" is a nonrestrictive phrase and should be set off with commas.

To understand why this is the case, it's helpful to first understand the difference between restrictive and nonrestrictive phrases. A restrictive phrase provides essential information to identify or define the noun it modifies, while a nonrestrictive phrase provides additional, nonessential information.

In Sentence B, the phrase "Hats knitted by my mother" is nonrestrictive because it adds extra information about the hats but is not necessary to identify or define them. The main point of the sentence is that hats are worn all winter by the family, not specifically the hats made by the mother. Therefore, the phrase should be offset with commas to indicate that it is nonrestrictive:

"Hats, knitted by my mother, are worn all winter by my family."

By using commas to set off the nonrestrictive phrase, we make it clear that the information about the mother knitting the hats is not essential to the sentence's meaning.