Choose the correct form of the verb. They ... (work) in the film industry since 2008.

The correct answer is "have worked".

The sentence "They ... (work) in the film industry since 2008" requires the Present Perfect tense because it describes an action that started in the past (2008) and continues to the present. The Present Perfect tense is formed using "have/has + past participle". Since the subject is "They", the correct auxiliary verb is "have".

Correct answer: have worked