Final answer:
A nonrestrictive clause was added to the sentence using parentheses, providing additional information about the dad's baking skills without altering the main sentence's meaning.
Step-by-step explanation:
To add a nonrestrictive element to the sentence using parenthesis, we could include extra information about the cookies or the event of baking. Here is a sentence with a nonrestrictive clause added:
My dad (who is a fantastic baker) baked us oatmeal chocolate chip cookies for dessert.
This addition provides extra information about the dad, but it is not essential to the meaning of the main clause. Thus, it is a nonrestrictive element because removing the information within the parentheses would not change the fundamental meaning of the sentence.
To add a nonrestrictive element to the sentence, we can use parentheses. For example, we can rewrite the sentence as: My dad (who is an excellent baker) baked us oatmeal chocolate chip cookies for dessert.