George, a Freelance Security Auditor and Penetration Tester, Was Working

George, a freelance Security Auditor and Penetration Tester, was working on a pen testing assignment for Xsecurity. George is an ESCA certified professional and was following the LPT methodology in performing a comprehensive security assessment of the company. After the initial reconnaissance, scanning and enumeration phases, he successfully recovered a user password and was able to log on to a Linux machine located on the network. He was also able to access the /etc/passwd file; however, the passwords were stored as a single "x" character. What will George do to recover the actual encrypted passwords?

A) George will perform sniffing to capture the actual passwords
B) George will perform replay attack to collect the actual passwords
C) George will escalate his privilege to root level and look for /etc/shadow file
D) George will perform a password attack using the pre-computed hashes also known as a rainbow attack