When did the caste system evolve into a four tiered hierarchy?

a.) when the aryans ruled over the region
b.) when the arabs ruled over the region
c.) when the mongols ruled over the region
d.) when the gupta empire ruled over the region

c. as a force against soviet invasion of afghanistan

hr2520 is the patient's act. there is required the secretary of health to summon a committee to develop a national strategic plan of prevention. this committee has forth provisions that make possible for the govern entities to acquire private health insurance services.

is easier to keep this hr2520 as federal, because that way the secretary of health has centralized power to deal with private insurance companies and the federas government has more ways and power to negotiate with them, than doing this process state by state in their specific terms.