Each of the following is a theory about the origin and purpose of the caste system in India except: ...

Each of the following is a theory about the origin and purpose of the caste system in India except:
 
  a. castes are based on a concept of pure and impure substances devised to regulate boundaries between different groups.
  b. castes are an ancient form of political factions that emerged from the imperial time period and are continued today.
  c. castes emerged from the Hindu practice of purity and impurity as far as contact with impure substances; it reflects occupational groups.
  d. it is a system that emerged from the Indian history of four classes and the hierarchy among these groups; each represents different statuses and power.