Final answer:
Option A is an opinion rather than a fact.
Step-by-step explanation:
The statement that is an opinion rather than a fact is option A: Kublai Khan was the greatest emperor in Chinese history. This statement is subjective and open to interpretation as different individuals may have different opinions on who they believe was the greatest emperor. In contrast, the other options (B, C, and D) provide factual information about Kublai Khan's lineage, military campaigns, and establishment of the Yuan dynasty.
Learn more about Opinions and facts in history