Which of the Following Scenarios Would Make a DNS Sinkhole

Which of the following scenarios would make a DNS sinkhole effective in thwarting an attack?

A) An attacker is sniffing traffic to port 53, and the server is managed using unencrypted usernames and passwords.
B) An organization is experiencing excessive traffic on port 53 and suspects an attacker is trying to DoS the domain name server.
C) Malware is trying to resolve an unregistered domain name to determine if it is running in an isolated sandbox.
D) DNS routing tables have been compromised, and an attacker is rerouting traffic to malicious websites.