It is only vehicles? Or can it be other things too. But trains also require a ticket.
Answer:
According to one long-held theory about the origins of South Asia's caste system, Aryans from central Asia invaded South Asia and introduced the caste system as a means of controlling the local populations. The Aryans defined key roles in society, then assigned groups of people to them.
Explanation:
Out of which priests emerged victorious to supreme their power over India. ... The caste system is a significant social system in India. One's caste affects their options regarding marriage, employment, education, economies, mobility, housing and politics, among others.
