To solve the issue of lack of governance in making changes to Salesforce, a data architect should recommend creating and managing a data dictionary and setting up a governance process for changes made to common objects. A data dictionary is a document that defines the metadata, structure, and relationship of each object and field in Salesforce. A governance process is a set of rules and procedures that govern how changes are proposed, reviewed, approved, and deployed in Salesforce. These measures will help NTO to maintain consistency, quality, and clarity of their data model and avoid confusion and errors among users. Option A is incorrect because adding description fields to explain why the field is used, and marking the field as required will not prevent unauthorized or unnecessary changes to Salesforce. Option C is incorrect because creating reports to identify which users are leaving blank, and using external data sources to augment the missing data will not address the root cause of the issue, which is the lack of governance in making changes to Salesforce. Option D is incorrect because creating validation rules with error messages to explain why the fields are used will not stop users from seeing new fields on their page that they are unsure of.