What is the dominant rhetorical effect of the opening question of al-Ghāshiyah?

Supplementary Practice 28 — Comparative Rhetoric of Sūrat al-Aʿlā and Sūrat al-Ghāshiyah

• Asking the date of the event
• Arousing attention, anticipation and awe
• Primarily waiting for a yes/no response
• Making a legal obligation through a question