An audio file contains 60 seconds of music, which was recorded at a 20 KHz sampling rate in stereo. Both channels were recorded at 12 bits per channel per sample. How big is the file? 38.4 Megabits. a. 28.8 Megabits. Ob. 38.4 Gigabits. C. 4800 KHz. d. 28.8 Gigabits. O e