Solution:

A denial-of-service (DoS) is any type of attack where the attackers (hackers) attempt to prevent legitimate users from accessing the service. Phishing is a type of social engineering attack often used to steal user data, including login credentials and credit card numbers. A whaling attack is a method used by cyber criminals to masquerade as a senior player at an organization and directly target senior or other important individuals at an organization, with the aim of stealing money or sensitive information or gaining access to their computer systems for criminal purposes.