Explain which implementation of the protection matrix is more suitable for the following operations: (a) Granting read

Question:

Explain which implementation of the protection matrix is more suitable for the following operations:
(a) Granting read access to a file for all users.
(b) Revoking write access to a file from all users.
(c) Granting write access to a file to John, Lisa, Christie, and Jeff.
(d) Revoking execute access to a file from Jana, Mike, Molly, and Shane.