The Most Serious Disadvantage of Observation Is ________

The most serious disadvantage of observation is ________.

A) if the observed phenomenon occurs frequently or is of short duration,observational methods may be cheaper and faster than survey methods
B) the reasons for the observed behavior may not be determined because little is known about the underlying motives,beliefs,attitudes,and preferences
C) observational methods permit measurement of actual behavior rather than reports of intended or preferred behavior
D) observational data is often time consuming and expensive and it is difficult to observe certain forms of behavior,such as personal activities