The caste system was the dominant social system of "India," since it had pre-modern roots in this area and helped build a system of social stratification, which was altered by British rule.
Aristotle was the student of Plato
There was a short period of official persecution under Emperor Decius, but the Roman Emperor who was really responsible for widespread persecution of Christians was Emperor Diocletian.
An opinion question so no one gets a right or wrong answer. Just say you have pros and cons on the unit and pick a random part and say that it was the most memorable part.