Answer:
Pavlov's Dogs and Discovery of Classical Conditioning. Pavlov's dog experiments played a critical role in the discovery of one of the most important concepts in psychology. While it was originally discovered quite by accident, these famous experiments led to the discovery of classical conditioning.
Explanation:
People don't want to read what is historical, they want to read about adventures and story telling about how they could be better, no one would buy a book that no one wants to read.
Your answer is d, because the man was speaking for himself :)