Which sentence is written correctly?



I replied that the new music teacher had a certain “ je ne sais quoi.”

I replied that the new music teacher had a certain je ne sais quoi.

I replied that the new music teacher had a certain “je ne sais quoi.”

I replied that “the new music teacher had a certain je ne sais quoi.”

The sentence written correctly is: "I replied that the new music teacher had a certain 'je ne sais quoi'."