If a fast-moving car making a loud noise approaches and moves past the person, what will happen as the distance between the two increases? a. the pitch of the sound being heard by the person will appear to be higher than the pitch of the source. b. the frequency of the sound waves reaching the person's ear will be greater than the frequency of the waves leaving the car. c. the pitch of the sound being heard by the person will appear to be lower than the pitch of the source. d. the pitch and frequency of the sound waves reaching the person's ear will remain unchanged.