What is the airport code for Louisville?

The airport code for Louisville is indeed SDF. This code corresponds to Louisville International Airport, which serves the city of Louisville, Kentucky. The "SDF" designation comes from the airport's historical name, Standiford Field, where it is located. Airport codes are typically derived from a reference to the airport's name or location, making it easy for travelers to identify the airport associated with a particular city.

In the given options, the other airport codes refer to different airports. For example, LHR is the code for London Heathrow Airport, SJD is associated with Los Cabos International Airport in Mexico, and LIH is the code for Lihue Airport in Hawaii. Understanding these codes helps travelers and aviation enthusiasts recognize airport locations quickly and accurately.