Your FTP server has been under attack, and the ISP of the attacker has been less than helpful in
mitigating the attacks. So you decide that all connections from that ISP (badguy.example.org) to
your FTP server will be denied and sent a message. Which line in your /etc/hosts.allow will have
the desired effect?

A.
in.ftpd : .badguy.example.org : twist 450 denied due to numerous attacks from this domain

B.
ftp : badguy.example.org : DENIED message 450 denied due to numerous attacks from this
domain

C.
in.ftpd : badguy.example.org : spawn echo 450 denied due to numerous attacks from this
domain

D.
ftp : .badguy.example.org : DENIED due to numerous attacks from this domain

Explanation:
man hosts. allow + man hosts options