Answer:
The ranking of the stars are 5 → 2 → 4 → 3 → 1
Explanation:
To solve the question, we note that an approaching star has a blue-shift, a regressing star has a red-shift and a crossing star will have no shift.
The magnitude of the blue-shift or red-shift is dependent on the speed of the stars.
Therefore we have the rank of the stars based on the Doppler shift that would be detected on earth from largest blue-shift to largest red-shift given as
5 → 2 → 4 → 3 → 1.