Which call sign is associated with American Airlines?

The call sign associated with American Airlines is "American." Call signs are used by airlines for both operational and communication purposes and often reflect the name of the airline itself. In this case, "American" directly ties to American Airlines, making it the appropriate choice to represent the airline in flight operations and radio communications.

The other choices represent different airlines— "Brickyard" is commonly associated with a different carrier, while "Delta" and "United" are the call signs for Delta Air Lines and United Airlines, respectively. Thus, those options do not correctly represent American Airlines.