Which of the Following Was NOT Mentioned in the Textbook

Multiple Choice

Which of the following was NOT mentioned in the textbook as an advantage of observational data?

A) Subjects react in a natural manner.
B) It is the only way to gather certain information (i.e.from children) .
C) Recall error is maximized.
D) Sometimes observational data may be obtained at less cost.
E) Sometimes observational data may be more accurate.