Some regions along the plane of the milky way appear dark because a) there are no stars in these regions. b) stars in these regions are hidden by interstellar gas. c) stars in these regions are hidden by interstellar dust grains. d) all the stars in these regions are very faint brown dwarfs. e) black holes trap the star light from these regions.

Explanation:

Some areas of the Milky Way seem dark because those are areas of the galaxy that are hidden by huge columns of interstellar dust that we cannot see through the visible range of the electromagnetic spectrum (which is the range in which our eyes see).

However, to solve this problem, astronomers use telescopes that work in the range of infrared and radio waves, to observe a little more through this intersetelar dust.