Write the command line to do the following tasks. a: Permit group to read and write, others to read and execute, the user to read, write and execute for the file diode.txt in the text mode. b: Permit the user to read and write, group to only read and execute, others can only execute for the file eptac.txt in numeric mode. c: Change the default permissions to read-only to everyone. d: Display the default permission for files you have changed. e: Change the group ownership of any file