A star with a continuous spectrum shines through a cool interstellar cloud composed primarily of hydrogen. The cloud is falling inward toward the star (and away from Earth). Which best describes the spectrum seen by an Earthbound observer?

a) blueshifted hydrogen emission lines
b) blueshifted hydrogen absorption lines
c) redshifted hydrogen emission lines
d) redshifted hydrogen absorption lines
e) a redshifted hydrogen continuum