The term used to describe the doppler shift in wavelength of light emitted by a star moving away from the earth is:

a. longitudinal shift

b. transverse shift

c. redshift

d. blueshift

Option (C)

Explanation:

In the field of astronomy, the redshift is defined as the shifting of the wavelength of light towards the red color of the spectrum. It describes about how the universe is expanding in every direction. The scientists have observed that the light in the universe emitted from distant objects such as the stars and galaxies is redshifted. This provides an example of Doppler's effect that is generally defined as the change in the wavelength of a wave that occurs when an observer moves relative to the source of the wave.

Hence, the correct answer is option (C).