In “waṣala al-ʿummālu wa-hum yaḥmilūna al-adawāt,” what role does “hum” play?

Supplementary Practice 12: Rhetorical Evidence, Competing Analyses and Reasoned Revision

• Merely a substitute for coordinating wāw
• The object of the verb “arrived”
• The subject of the circumstantial nominal clause and a link to the workers
• The agent of a conditional verb