In the Salesforce Lightning Experience, the buttons and actions that appear in the header (Highlights Panel) of a record are controlled by the Salesforce Mobile and Lightning Experience Actions section of the Page Layout. If a specific action like "Log a Call" is missing, it is usually because it has not been dragged into this specific section in the Page Layout editor. While standard actions sometimes appear in the Activity component (Option A), they are explicitly configured for the header via the Page Layout. There is no specific "Log a Call permission" (Options C and D) that would hide only that button; if a user has permission to create Tasks, they generally have the ability to use the Log a Call feature if it is present on the layout.