Answer:
A. Doxing
Step-by-step explanation:
Doxing is a term used to describe the act of individuals who generate or search for private information of people with a malicious intent of using those private information as a form of blackmail. They often request for a sum of money from the owners of such private individuals, thereby threatening the individuals to release the content to the public if they fail to cooperate.
This is the tactic that David used in the collection of private information of individuals.