The head related transfer function (HRTF) is caused by and provides information about Select one: a. the nature of the sound source ; where the sound is coming from O b. changes to the sound intensity due to a person's height; distance to a sound O c. changes to the sound spectra due to the shape of the head and pinnae ; location of a sound on the azimuth O d. changes to the sound spectra due to the shape of the head and pinnae ; sound elevation O e. a and c