Hello, I am having trouble with these question

Arguably, the most secure encryption / decryption algorithm, called Rijndael, that is used for the advanced encryption system (AES) in USA is not a secret. It is available in public domain which makes it more secure because the adversary can try breaking it if thet can. Having an algorithm in public domain like this is an example of the security design practice called authorization. minimization of implementation. least astonishment. open design. QUESTION 8 Vulnerabilities in a software or hardware system are not always known. The ones that are not known are called zero-day vulnerabilities because once they are discovered by the avdersary, you have zero days to do something. The vendors usually find a solution as soon as they discover a zero-day vulnerability and contact the buyers directly to either update their softeare or send them the solution. This design practice is called usability. updates and patches. backups and restorations. logging and auditing. QUESTION 9 The router that we bought had the options to have secure communications with multiple brands, but we use only one brant. Therefore, we turned off the security features regarding all other brands. This is an example of a design practice. separation of domain. minimization of implementation. updates and patching. least privilege