In the Salesforce Lightning Experience, the fields displayed in the 'header' of a record and on the cards in the Kanban view are controlled by the Compact Layout. Each object has a System Default compact layout, but a Platform Administrator can create custom ones to prioritize the most important information, such as 'Account Name' and 'Close Date.' By editing the primary compact layout for the Opportunity object, the admin directly controls which fields the sales team sees as they drag and drop deals through the Kanban stages. While Page Layouts (Option C) control the main record detail page and Kanban Settings (Option D) control which field is used for columns and summaries, the individual 'card' content is always driven by the Compact Layout. This ensures that users can quickly gather key context without needing to open every individual record.