experience an increase in their amplitude. experience an increase in frequency. experience a decrease from transverse waves to longitudinal waves. experience a decrease in frequency.
I gave my students this multiple choice question: Based on the Doppler effect, the electromagnetic waves reaching Earth from a galaxy that is moving away from Earth would be expected to

Only one answer is correct among these 4 choices:
- experience an increase in their amplitude.
- experience an increase in frequency.
- experience a decrease from transverse waves to longitudinal waves.
- experience a decrease in frequency.

Could you tell me which one is correct?

experience a decrease in frequency.