First, consider case A: An observer flies in a plane toward a stationary 600 Hz siren at 1/4 the speed of sound. Now consider case B: a plane carries a 600 Hz siren at 1/4 the speed of sound towards the observer in the airport tower. Which of the following situations has the largest Doppler shift for the observer? Group of answer choices Case A: observer in the moving plane Case B: observer in the stationary tower Both will have equal Doppler shifts