By the lack of details, only you can know that for sure...
Answer: memory implantation
Explanation: in psychology, memory implantation is a method used to learn about the memory of human beings. In it, people are made to beieve in some fake memories in their head as a true memory. This technique started in 1900 and is used in cognitive psychology. It is a difficult process but it is possibility is higher also.
i am so sorry im taking up the answer spot but i have to say the answer is not d im not sure what it is but its not d!
Yeah it is a rational psychology
