I looked this question up and found that the underlined elements are:
a talented painter
at the top of the stairs
who is very excited
that I baked today
Answer:
Nonrestrictive:
a talented painter
who is very excited
Restrictive:
at the top of the stairs
that I baked today
Step-by-step explanation:
The elements that are placed between commas are nonrestrictive. They are not essential for the speaker to express meaning in the sentence. If removed, they would technically not make that much of a difference, the most important part of the message being conveyed anyway.
On the other hand, restrictive elements are not placed between commas. They are essential for the meaning of the sentence to be complete. For instance, in the sentence "He will stay in the room at the top of the stairs," the restrictive element determines which room the uncle will be staying in. If we remove it, the sentence could refer to any room.