CompTIA Security Plus Mock Test Q1239

Ann a security technician receives a report from a user that is unable to access an offsite SSN server. Ann checks the firewall and sees the following rules:
Allow TCP 80
Allow TCP 443
Deny TCP 23
Deny TCP 20
Deny TCP 21
Which of the following is preventing the users from accessing the SSH server?

A. Deny TCP 20
B. Deny TCP 21
C. Deny TCP 23
D. Implicit deny

Correct Answer: D
Section: Mixed Questions