Final answer:
A process with EUID 4 and EGID 7 can execute a file with UID 4, GID 9, and permissions rw-r-x--x because the process's EUID matches the file's UID, granting it read and execute permissions.
Step-by-step explanation:
When a process with an effective user id (EUID) of 4 and an effective group id (EGID) of 7 attempts to execute a file with a user id (UID) of 4, group id (GID) of 9, and permissions rw-r-x--x (read and write for the user, read and execute for the group, and execute for others), the process will be allowed to execute the file. This is because the EUID of the process matches the UID of the file, allowing it to use the user permissions set on the file. Since the permissions allow the user to read and execute the file (rw-), the process can execute the file.