What does the airport code SNA refer to?

The airport code SNA refers to John Wayne Airport, which is located in Santa Ana, California. This airport serves the greater Orange County area. The name "John Wayne Airport" reflects its association with the famous actor who resided in Orange County, and it is a well-known regional airport providing both domestic and limited international flights.

The other options refer to different cities with their own airport codes. Sarasota, Florida, has the airport code SRQ; Salt Lake City, Utah, is represented by SLC; and Seattle, Washington, has SEA as its airport code. The specificity of SNA to Santa Ana is why it is the correct answer in this context.