ORD is the airport code for which major city?

ORD is the airport code for Chicago O'Hare International Airport, which is one of the busiest airports in the United States and serves as a major hub for Delta and other airlines. The designation "ORD" is derived from the original name of the airport, Orchard Field, which reflects its historical connection to the area. Chicago O'Hare plays a significant role in both domestic and international travel, making it a key gateway city for air traffic.

Choosing this correct answer demonstrates an understanding of the airport codes that are commonly associated with major transportation hubs. Other options may represent valid cities with their own airports; however, they do not correspond to the ORD airport code. This emphasizes the importance of familiarizing oneself with airport identifier codes to navigate travel logistics effectively.