Choose the True Statements Regarding the Disadvantages of Observational Methods

Choose the true statements regarding the disadvantages of observational methods.

A) They may increase subject reactivity.
B) When a single interrater is used and observations are opposite, there is no way to resolve the conflict, since each is equally correct.
C) They may be used for both quantitative and qualitative research.
D) They are more subjective than other types of measurements.
E) They allow real-time capture of data.
F) They are invariably subject to skepticism unless verified in some manner.