Final answer:
To secure the C:\Admins folder, encrypt it and add Susan as an authorized user for the Passwords.xls file.
Step-by-step explanation:
To secure the contents of the C:\Admins folder, you can encrypt it using file and folder encryption tools provided by the operating system or third-party software. Encrypting the folder will ensure that unauthorized users cannot view the documents inside. To add Susan as an authorized user for the C:\Admins\Passwords.xls file, you can modify the file's permissions to grant her the necessary access.