Drag each restrictive or nonrestrictive element into the
correct category
My uncle, a talented painter, is coming to visit
tomorrow. He will stay in the room
at the top of the stairs. My mom, who is very excited, is
throwing a party in his honor. She will serve the
cookies that I baked today.

Restrictive

that I baked today

at the top of the stair

Non Restrictive

a talented painter

who is very excited

Explanation:

Restrictive clauses or phrases are those that modify or transform the meaning of the noun that precedes them tangibly and that are such that without the noun present would make no sense with the sentence. They are usually used without  any sort of punctuation.

Non restrictive clauses describe the noun they are preceded by but do not tangibly transform it but only add to the overall description of the said noun. Thus, they are used with commas as in the above case.

the reason that neiterkob's daughter most likely tell the beginnings of the maasai is : to explain the readers the origin of maasai culture

with this explanation, the reader will grasp a better concept about it and not lost in the middle of reading.

                                            (hope this )

what excerpt? i would generally think a.