Answer:
The correct answer is "Red shift"
Explanation:
Blue shift: When the source and observer approach one another, the evident frequency increments or apparent wavelength diminishes. Here the Doppler shift is positive. This is known as blue shift.
Red shift: When the source and observer move away from one another, the clear frequency diminishes or apparent wavelength increments. Here the Doppler shift is negative. This is known as red shift.
If there’s a all above answer on it it’s all of them
