Answer-
A conspiracies theory is an idea that is made by a person or group of people that explains a phenomenon, place blame onto someone, or questions a logic, idea, or belief. They can be religious, political, social, or just random ideas that people take to believe and use, many times with ill-intent.
A conspiracy in "A Study in Scarlet" is the death of Hope's future father-in-law. The conspiracy that surrounds him is he has killed him and why.
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