Which of the Following Was NOT Discussed in the Textbook

Which of the following was NOT discussed in the textbook as conditions for the use of an observation study?

A) If there is a short time interval between the beginning and end of the behaviour to be observed the condition is favourable.
B) If the behaviour must be amenable to physiological measurement than the condition is favourable.
C) If the behaviour is public and therefore readily observed the condition is favourable.
D) If the behaviour is so automatic or repetitive that any personal recall on the respondent's part is likely to be faulty the condition is favourable.
E) If there is a very long time interval between the beginning and end of a behaviour that observation would be impractical the condition is unfavourable.