Final answer:
To prevent users from changing data displayed by the form while Brendan is working on it, he can disable the form or restrict user access by locking or hiding the form.
Step-by-step explanation:
To prevent the users from changing data displayed by the form while Brendan is working on it, he can disable the form. This will make the form non-editable and would allow users to only view the data without making any changes. Additionally, if Brendan wants to restrict user access to the form entirely, he can lock the form or hide the form. Locking the form would require some form of authentication or password to access it, while hiding the form would make it completely invisible to users.