Which sentence is written in compliance with the guidelines for commas?
the famous author, judy blume, is coming to speak at our school.
the famous author, judy blume is coming to speak at our school.
the famous author judy blume is coming, to speak at our school.
the famous author judy blume is coming to speak at our school.

Option (iv) is the correct answer.  

The famous author Judy Blume is coming to speak at our school.

This is the case of use of commas with appositives. An appositive is a word or phrase or clause that identifies the noun/noun phrase that precedes it.  

Commas are used to set off the appositive from the noun/noun phrase that it identifies if the appositive is not essential to understand the meaning of the noun/noun phrase and is only providing an extra information. In case the noun/noun phrase itself does not convey the complete meaning and an appositive is essential to understand the complete meaning of the sentence then commas are not used to set it off from the noun/noun phrase.

In this question, the noun 'author' does not convey complete information and the appositive 'Judy Blume' is essential to properly understand its meaning. Here appositive is an essential part of the sentence and is not meant to provide any extra information. Hence, commas should not be used to set the appositive off from the noun. Thus option "The famous author Judy Blume is coming to speak at our school" is the correct answer.

just took the quiz and this is the right answer

the correct answer is (a); the angles, saxons, jutes, picts, and celts

explanation:

the answer is decimated