A Chamber Orchestra hired by Experience Washington $($The State of Washington Tourism Board$)$ staged a series of seemingly impromptu performances of a medley of Nirvana songs, including "Smells Like Teen Spirit" and "Come as You Are," in busy airport terminals around the country. This is an example of $\_\_\_\_\_\_\_\_.$

Group of answer choices

Lobbying

Guerrilla marketing

Sponsorship

Media relations

Internal PR