Final answer:
The writer at the conference read his work in Arabic, reflecting on its historical significance as a unifying language across vast regions.
Step-by-step explanation:
The writer at the conference read his work in his original, non-English language, which was Arabic. This fact mirrors historical occurrences where Arabic served as a lingua franca across various regions, as indicated by the historical information that Arabic replaced the vernacular in lands conquered during Arab conquests. Moreover, it was the single language that facilitated trade and intellectual exchange from Spain to India, emphasizing the importance of Arabic historically.