The Crucial Principle of Research Is

The crucial principle of research is

A) the framework or plan for a study that guides the collection and analysis of data.
B) that 20% of the factors cause 80% of the problems.
C) to assess sampling error because it has the greatest impact on the study's results.
D) to isolate the variables and analysis technique at the first opportunity.
E) that the design of the investigation should stem from the problem.