What situation prompted someone to spring into action quickly?

The correct answer illustrates a scenario that involves urgency and the need for immediate action. A sudden announcement about a sale, which induces a rush of customers, creates an environment where quick thinking and responsiveness are crucial. Flight attendants and staff must react swiftly to manage the influx, assist customers, and ensure that operations run smoothly amidst the chaos brought about by the sale.

In contrast, while an unexpected inflight emergency (the first option) might also require quick action, the question specifically emphasizes a situation that prompts a rapid response from customers, making this choice more closely aligned with the context. Receiving a last-minute flight schedule change (the second option) might indeed require staff to act promptly, but it does not inherently involve the immediate need to respond to a crowd or customers. Similarly, a coworker's announcement about an important meeting (the fourth option) is typically planned and does not involve an urgent, spontaneous reaction from a larger group. Hence, the context of a sale announcement leading to customer urgency makes the selected choice the most fitting.