Ahistorian writes a book in which she organizes the history of europe into these units: the middle ages, the enlightenment, and the renaissance. this is an example of . periodizationb. historical interference c. continuity over timed. point of view

Periodization.

Periodization is the practice of dividing the past into separate blocks of time in order to facilitate the study of history. This categories are created based on some stable characteristics. However, the beginning and end of any period is often difficult to establish, as history is one continuous process, without any clear cut breaks.

The terms "Middle Ages," "Enlightenment," and "Renaissance" refer to this type of categories.

your list doesn't mention any of them at all.

and what does "these" mean anyway ?