In the accompanying diagram, the spectral lines of hydrogen gas from three galaxies, A, B, and C, are compared to the spectral lines of hydrogen gas observed in a laboratory.
What is the best inference that can be made concerning the movement of galaxies A, B, and C?
A. Galaxy A is moving away from Earth, but galaxies B and C are moving toward Earth. B. Galaxy B is moving away from Earth, but galaxies A and C are moving toward Earth. C. Galaxies A, B, and C are all moving toward Earth. D. Galaxies A, B, and C are all moving away from Earth.
