Answer:
Impromptu style.
Explanation:
There are four main styles of addressing or giving a speech- extemporaneous, impromptu, memorized, and manuscript. They all have their distinct styles depending on the preparation style, duration, and delivery.
In the case of asking someone to give a speech just 10 minutes before the act of speaking will be an impromptu style of delivery. This involves the person to think and make mental notes about his speech on the spot and not have any previous preparation and without much research.
Thus, the correct answer is an impromptu style.
