Which command is used to change permissions on files and directories?

A new file server is added to an existing network. Some users are able to connect to this server, while others are not. A partial network configuration on the server shows the following: Link local: fe80::3000:aff:dea6:f8c/64 Which of the following BEST explains why some users cannot connect to the server?

A. The users' workstations are configured to use DHCP. B. The users' workstations do not support IPv6. C. The users' workstations are not on the same network as the server. D. The user's workstations are configured with an incorrect subnet mask.

The __________ provides a mechanism for the user and application programs to communicate with the operating system and request operating system support.

a. application interface b. user interface c. file system d. program interface