Which city is associated with the airport code ORD?

The airport code ORD is associated with Chicago O'Hare International Airport, which is one of the major airports serving the city of Chicago, Illinois. The code itself originates from the name of the airport's original namesake, Edward O'Hare, a World War II hero. O'Hare has grown to become a significant hub for various airlines and is known for its extensive flight operations globally. The association with Chicago is further solidified by the airport's prominent role in air travel for the area, offering numerous domestic and international flights.

The other options do not correspond to the correct airport code. Oakland, Omaha, and Orlando each have their own unique airport codes, making them unrelated to the designation of ORD.