Final answer:
The correct conjugation of the verb 'extinguirse' for the subject 'ellos' is 'extinguen'.
Step-by-step explanation:
The verb 'extinguirse' is conjugated differently based on the subject. In this sentence, the subject is 'ellos', which is the third person plural. Therefore, the correct conjugation of 'extinguirse' is 'extinguen'.
Learn more about Conjugation of the verb 'extinguirse' in Spanish