A hacker could obtain passwords without the use of computer tools or programs through the technique of:

A.
social engineering.

B.
sniffers.

C.
back doors.

D.
Trojan horses.

Explanation:
Social engineering is based on the divulgence of private information through dialogues, interviews, inquiries,
etc., in which a user may be indiscreet regarding their or someone else’s personal data. A sniffer is a computer
tool to monitor the traffic in networks. Back doors are computer programs left by hackers to exploit
vulnerabilities. Trojan horses are computer programs that pretend to supplant a real program; thus, the
functionality of the program is not authorized and is usually maliciousin nature.