An ethical hacker conducts testing with full knowledge and permission.

White Hat Hacking is defined in CEH v13 as ethical hacking performed with explicit authorization to identify and remediate vulnerabilities. White hat hackers operate within legal frameworks and contractual agreements.

Grey hats act without permission but without malicious intent. Black hats conduct illegal attacks. Blue hats are external testers invited to find bugs before product release.

Thus, Option C is correct.