Answer: A. Social Engineering
Step-by-step explanation:
Social Engineering is manipulating or deceiving a victim in order to gain control or to steal personal and/or financial information.
Doxing is making someone's private information publically available(usually on the web)
Computer Monitoring is recording someone's input to a computer
And cyberbullying is ridiculing or intimidating someone via the web or online.
None of the descriptions match or fit like social engineering making it the best option.
Harold was definitely socially engineered to give his credit card info.