please provide the correct answer

3. A file owner wanted to grant full permissions for himself on the file: myfile.ext, read only for his group and he wanted to forbid everyone else from accessing the file. The correct symbolic notation for the file permissions is a) -rwx-op-xx b) - rnor--XXX c)-rwxr----- d) - r--rwx-x 4. A file owner wanted to change file permissions to a file so that the new permissions would allow the file owner to read and execute, and deny anybody else all access. The correct new permissions on the file in octal notation would be a) 0400 b) 0644 c) 0500 d) 0570 5. In cyber risk management, the risk by buying a cyber insurance policy is considered as a risk response when considering risk scenarios where investment in security controls is very high. a) Accepting b) Mitigating c) Avoiding d) Transferring 7. A(n) virus is a virus that mutates with every infection by adding padding code, making detection by the "signature" of the virus impossible. a) encrypted b) polymorphic c) stealth d) metamorphic 8. When analyzing cyber attacks, a cyber analyst could use to understand the different stages of the cyber attack and to map used tactics and techniques. a) NIST Cybersecurity Framework b) IRAM Risk Management Framework c) MITRE ATT&CK Framework d) NERC CIP 9. In the Needham-Schroeder With Denning-Sacco Modification Key exchange protocol, adding can prevent a) Replay attacks in first step b) Eve impersonating Alice in conversation with Cathy c) Replay attacks in third step d) Eve impersonating Bob in response to Alice 10. When using public key cryptography, to establish the goal of non-repudiation, the plain-text message from the sender is encrypted using: a) Recipient's public key b) Sender's public key and a shared secret key c) Recipient's private key d) Sender's private key