Answer: D - Determine which events caused the most changes between
historical periods.
Step-by-step explanation:
Historians take significant events as milestones that have had a high impact in the world and have determined the historical course to a greater or lesser extent.
For example, the beginning of the Middle Ages, or the end of the ancient period, take the fall of the Western Roman Empire 476th year and lasts until the discovery of America in 1492. These two major historical events brought about tremendous changes in the past of human society and markedly determined the future history course.