Final answer:
The correct form of the verb 'venir' in this sentence is 'viennent'. It means to come and is conjugated in the third person plural form to match the subject 'Ils'.
Step-by-step explanation:
The correct form of the verb venir in this sentence is viennent. Therefore, the sentence should be:
Ils viennent à la danse.
The verb venir means to come in English. In this sentence, it is conjugated in the third person plural form to match the subject Ils which means they.
Learn more about Verb Conjugation