Final answer:
Timgad, located in Algeria, was founded around 100 CE, aligning with option 2 from the available choices.
Step-by-step explanation:
The ancient Roman city of Timgad in Algeria was founded around the year 100 CE (Common Era), which corresponds to option 2 in the question provided. This period falls into the classical period of Roman expansion and urbanization.
It is important to note that before the modern era, different civilizations had their own calendars and ways of marking time. However, in contemporary historical study, we use the BCE (Before Common Era) and CE (Common Era) system as a standardized way to reference time.