Question

compared to the spectral lines observed in the laboratory, the spectral lines observed in the light from the distant star have shifted toward... the blue end of the spectrum, indicating the star’s movement toward earth. the red end of the spectrum, indicating the star’s movement away from earth. the blue end of the spectrum, indicating the star’s movement away from earth. the red end of the spectrum, indicating the star’s movement toward earth.

Explanation:

The problem is about the Doppler shift in stellar spectra. When a star moves away from Earth, its spectral lines shift toward the red end of the spectrum (redshift), and when moving toward Earth, they shift toward the blue end (blueshift). The question states the spectral lines from the distant star shifted toward the red end, so we match this to the option describing red - shifted spectrum (indicating movement away from Earth).

Answer:

The red end of the spectrum, indicating the star’s movement away from Earth. (The option with this description, likely the purple - colored card text: "The red end of the spectrum, indicating the star’s movement away from Earth.")