This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Psychiatry
Loss of capability of doing goal-directed things, to express ideas, making irrelevant comments, but ultimately succeeding in going back to the original point is known as - 
Select and explain. 
A. Commnentalism, B. Tangentiality, C. Dysprosodia, D. Circumstantiality
D: Circumstantiality
Answer: D: Circumstantiality 
Explanation: Both circumstantiality and tangentiality have degression into unnecessary irrelevant details. However:-


In circumstantiality, thought reaches its ultimate goal in a long and roundabout manner, i.e. the patient return back to the original theme after degression.
In tangentiality, the goal is not reached and the thought is sidetracked more and more away from the natural end and never returns to the original theme.