Which of the following indicates that the universe is expanding? a) blue shift of distant galaxies b) blue shift in the milky way c) red shift on distant galaxies d) red shift of the galaxies in the local group

Option (C)

Explanation:

In terms of astronomy, the redshift is often referred to as the shifting of the wavelength of the light towards the red color of the spectrum. This provided a piece of information that helped in understanding how the universe is expanding in all the direction. The scientists have observed that the light in the universe emitted from distant objects such as the stars and galaxies is redshifted. This is an example of Doppler's effect which is defined as the change in the wavelength of a wave that occurs when the observer moves relative to the source of wave.

Thus, the redshifting of distant galaxies indicates that the universe is constantly expanding and it is theoretically proved.

Hence, the correct answer is option (C).