Is the part a only Cathy?

also provide correct answers for all parts

and detailed explanation

10. (10 pts) The following table shows the access control list of a UNIX filesystem. The second column of Permission gives suid/sgid/sticky bits, where suid is the most significant bit. Alice and Bob are in the same group CS, while Cathy is in another group EE. 'a.out' is an executable program. (a) (2 pts) In Alice, Bob, and Cathy, who can read 'c.txt'. (b) (2 pts) In Alice, Bob, and Cathy, who can change the content of 'b.txt'? (c) (6 pts) When Bob executes 'a.out', what are the ruid and euid of the process