Question

\girl you better start studying for your comma quiz,\ advised charlotte, who was always nagging mary lou ellen about doing homework.

no change is necessary.
remove the comma between quiz and advised.
add a comma between girl and you.
remove the comma between charlotte and who.

Explanation:

1. The phrase "Girl you better..." is a direct address, so a comma must separate the noun of direct address ("Girl") from the rest of the sentence.
2. The comma after "quiz" is correct, as it closes a direct quote before the dialogue tag "advised Charlotte".
3. The comma before "who" is correct, as "who was always nagging..." is a non-restrictive clause that provides extra, non-essential information about Charlotte.

Answer:

Add a comma between Girl and you.