Final answer:
A guide to the NFL should include headings that provide essential information such as 'Players and Teams' and 'Ticket Prices for Matches,' which are directly related to the NFL.
Step-by-step explanation:
When creating a guide to the NFL using the NFL website, certain headings are essential to include for the information to be comprehensive and useful to users. These would typically cover fundamental aspects of the NFL. In this case, the most relevant heading to include would be A. Players and Teams, as this provides direct information about the core components of the league, the teams that compete, and the players that make up those teams. Heading C. Ticket Prices for Matches could also be relevant, offering essential details for fans looking to attend games. Contrarily, headings such as B. Weather Conditions during Matches and D. Popular Restaurants near Stadiums may not be necessary for a basic guide to the NFL, as they are more ancillary information and not directly related to the NFL's operations.