Which call sign is associated with Delta Airlines?

Delta Airlines has the call sign "Delta," which is an important identifier used in aviation operations. Air traffic controllers use call signs to communicate with pilots and facilitate clear communication. The use of the name "Delta" is straightforward as it directly correlates with the airline's name, making it easy to recognize and remember.

This direct association helps to avoid any potential confusion with other airlines during critical flight operations or emergencies. The other options mentioned refer to different airlines or names that do not apply to Delta. American and United are call signs for American Airlines and United Airlines, respectively, while "Brickyard" is associated with the Indianapolis Motor Speedway, not an airline. Thus, the choice of "Delta" stands as the correct call sign for Delta Airlines.