The suggested answer is A, C.
IP reputation leverages many techniques for accurate, early, and frequently updated identification of compromised and malicious clients so you can block attackers before they target your servers.
IP blacklisting is a method used to filter out illegitimate or malicious IP addresses from accessing your networks. Blacklists are lists containing ranges of or individual IP addresses that you want to block.
Reference:
https://docs.fortinet.com/document/fortiweb/6.3.5/administration-guide/137271/blacklisting-whitelisting-clients https://www.imperva.com/learn/application-security/ip-blacklist/