Which of the following are needed to properly maintain the ethical hacking mindset?

a$.$ Pen testers must be careful to conduct themselves ethically with professionalism and integrity.

b$.$ Pen testers must not accidentally stray into the realm of the malicious hacker and cause damage to systems or data.

c$.$ Pen testers must do no harm and stay within the boundaries of what activities have been specified and sanctioned in the penetration testing agreement documents.

d$.$ All of these are correct.