Mostly because the Roman empire was a hugely vast empire in time where the internet or any other form of fast communication possibilities didn't exist yet. For this reason, it would be highly unpractical for Rome to rely on having direct democracy and each person giving his vote on every aspect of life.
Answer:
language
Explanation:
Since it is showing all different languages
To be able to answer a question that involves a graph, I would need to see the graph :)
