Answer:
Option A, slow diffusion of the book.
Explanation:
The book contains the secret or tricks to win the game so as many as people will get the book the population of people who can win the game will increase. However, the winning of people in the game is the loss of a carnival operator because he has to give more winning amount. Therefore, the book will increase the winning probability of people so carnival operators will hope its slow diffusion so that people do not get to know the winning techniques.