Answer: (ii) A specific business area

'Subject-oriented' is one of the four defining characteristics of a data warehouse (the others being integrated, non-volatile and time-variant). It means the warehouse is organised around the major subjects of the enterprise — customers, products, sales, orders — i.e. a specific business area, rather than around the applications or day-to-day processes that happen to produce the data. Analysis then runs subject by subject across many years of history.

Individual transactions and day-to-day operations describe an OLTP system, which is application-oriented and holds current state; real-time data describes operational/real-time systems. A warehouse instead stores integrated, historical, subject-oriented data for decision support, so (i), (iii) and (iv) are incorrect.