Which of the Following Is a Disadvantage of Using Existing

Which of the following is a disadvantage of using existing sources of data for research?

A) Researchers often seek answers to questions the data doesn't directly address.
B) Researchers have to spend a great deal of time and money to get the data.
C) Researchers do not always understand how the data was interpreted or what it meant in its original context.
D) Researchers do not have access to existing sources.
E) Existing sources of date are never relevant to the contemporary world because they emerged from a different time and place.