The answer to this is about 36 percent.
The answer to your question is b
When we read "Ambush" we soon realize that it is quite true what one might suspect about O'Brien when we read about him - the fact that indeed he always seemed to wanted to hear emotional truth more than he did factual truth. There are multiple sentences which indicate this, but most commonly these are sentences when he starts talking and conceptualizing events in terms of their meaning, how they affected someone and how someone felt while they happened.
The greatest problem associated with detecting marijuana in urine is that it is difficult to determine when the individual actually used marijuana.