A custom field on an account is used to track finance information about a customer. Only members of the Finance Team have access to this field…

The most appropriate and recommended solution is to use a permission set. Profiles are intended to define the baseline access for a group of users with the same job function. When a single user requires additional, specific permissions that deviate from their profile, a permission set should be used. This approach adheres to the principle of least privilege by granting access only to the specified user without altering the permissions for all other users on the Customer Service Profile. This method is scalable, maintainable, and avoids the unnecessary creation of new profiles.

B. Create a new profile...: Creating a new profile for a single user is not a scalable or maintainable practice and leads to administrative overhead, often referred to as "profile proliferation."

C. Update the Customer Service Profile...: This would incorrectly grant access to the sensitive field to all users assigned the Customer Service Profile, violating the business requirement.

D. Update the custom field’s Field Level Security in setup...: Field-Level Security is not configured directly for individual users. It is managed through profiles and permission sets, which are then assigned to users.

1. Salesforce Help Documentation, "Permission Sets": "A permission set is a collection of settings and permissions that gives users access to various tools and functions. The settings and permissions in permission sets are also found in profiles, but permission sets extend users’ functional access without changing their profiles." This directly supports using a permission set to grant additive access to a specific user.

2. Salesforce Help Documentation, "Control Access to Fields": "After you set field-level security, you can create a permission set to grant access to a field that is hidden by the user’s profile." This page outlines the exact use case described in the question, confirming that a permission set is the correct tool to override profile-level field restrictions for specific users.

3. Trailhead, "Data Security" Module, "Control Access to Fields" Unit: "Use permission sets to grant additional access. For example, a user’s profile allows them to read and edit a field. But you have a user who also needs to delete records from that field. Instead of creating a profile, you can create a permission set that grants delete access and assign it to that user." This illustrates the core principle of using permission sets for exceptional, additive permissions.