What does the term “Ethical Hacking” mean?

What does the term "Ethical Hacking" mean?

A.
Someone who is hacking for ethical reasons.

B.
Someone who is using his/her skills for ethical reasons.

C.
Someone who is using his/her skills for defensive purposes.

D.
Someone who is using his/her skills for offensive purposes.

Explanation:
Ethical hacking is only about defending your self or your employer against malicious persons by using the same techniques and skills.