Final answer:
The fall of the Roman Empire resulted in the loss of architectural and engineering advancements, legal and governance systems, and preservation of classical literature and knowledge.
Step-by-step explanation:
The achievements that were lost when the Roman Empire fell include advancements in architecture and engineering, Roman law and governance systems, and the preservation of classical literature and knowledge. Therefore, the complete answer to the question is d) All of the above. The fall of the Roman Empire led to a period of instability that significantly impacted the maintenance and advancement of these areas. Architectural and engineering wonders were no longer constructed at the scale they once were; the sophisticated Roman legal system was replaced by various fragmented and localized systems; and the preservation of knowledge suffered, with many classical texts lost or solely preserved in isolated centers such as monasteries or in the Byzantine Empire.