Which of the Following Is a Limitation of Using Observation

Which of the following is a limitation of using observation as a manual audit procedure?

A) Observation provides information at a certain time and makes it difficult to draw representative conclusions.
B) Observation is not as persuasive as inquiry due to a lack of direct evidence.
C) Observation is performed specifically to test the validity of documented or recorded information.
D) Observation may cause individuals to behave less critically or carefully if they are aware that other forms of manual audit procedures have already taken place.