Answer:
A.
Step-by-step explanation:
'What trick-or-treating tells us about human nature ' is an article written by behavioral scientist, Dilip Soman. The article talks about how halloween gives behavioral scientists an insight into human behavior.
In first four paragraphs, Soman describes why behavioral scientists, like him, like Halloween. The behavioral scientists, as stated by Soman, are constantly seeking ways to study human behavior and choices made in natural environment. So, for them, Halloween is that natural habitat in which they study human conduct.
Therefore, option A is correct.