Answer: A. Primary sources may be incomplete or contradict other sources.
Explanation: The difficulty for historians in arriving at a universally accepted interpretation of past events is due to incomplete or conflicting primary sources, the time and perspective required for interpretation, biases and historiography, and the complexity of historical events with multiple perspectives.
Here's why: Historians rely on primary sources such as documents, letters, and artifacts to gather information about past events: however, these sources may be limited in number or may not provide a complete picture of the event.
In addition, a historical interpretation is often made long after the event has occurred; as time passes, new evidence may emerge, and new perspectives may be considered.
Furthermore, historians' interpretations can be influenced by their own biases, perspectives, and cultural backgrounds. Different historians may prioritize different aspects of an event or emphasize different causes and consequences.
Finally, historical events are often complex and multifaceted, involving various factors, actors, and motivations. Different individuals or groups may have different perspectives and experiences of the same event, leading to divergent interpretations.