Answer: answer might be D)identify turning points to act as the start and end points of historical eras
Explanation: As Periodization is the skill involves Dividing history into distinct and meaningful timeperiod.
So, main tasks of historians during the process of periodization includes, 1.Identify a timeperiod 2.criteria determination for periodization 3.divide the period into distinct periods 4.analyze the periods 5.evaluate the periodization.
As above what we get is Periodization allows historians to create a framework for understanding how events and trends relate to each other across time. Therefore, option D. which involves turning points to identify the start and end points of historical eras, sounds correct.