The Field Accessibility Viewer in Salesforce provides a quick and comprehensive way to check the visibility and accessibility of specific fields across different user profiles and page layouts. By using this tool, a System Administrator can efficiently determine which profiles have access to certain fields, how those fields are displayed (or not displayed) on various page layouts, and how they're affected by record types. This approach is much faster and more efficient than manually checking field-level security settings for each profile (Option B), logging in as users with different profiles to view the Account page layouts (Option C), or making fields universally required, which doesn't address visibility on specific page layouts or for specific profiles (Option D). The Field Accessibility Viewer centralizes this information, making it easier to audit and update field access as needed.