Final answer:
The buildings should be ordered as follows: The Pantheon, Rome (c. 125 CE), Arch of Constantine, Rome (315 CE), and Hagia Sophia, Istanbul (537 CE).
Step-by-step explanation:
The question pertains to ordering historical buildings according to the dates they were built. We can organize the provided buildings in chronological order based on the information given:
- The Pantheon, Rome - around 125 CE
- Arch of Constantine, Rome - dedicated in 315 CE
- Hagia Sophia, Istanbul - construction completed in 537 CE
Thus, the correct order from earliest to latest is the Pantheon, the Arch of Constantine, and then Hagia Sophia.