Which of the following reasons does NOT contribute to the darkness of the night sky

There are an enormous number of stars in the universe. A digital camera aimed at the nighttime sky will have many stars in every pixel of the camera’s focal plan. Which of the following reasons does NOT
contribute to the darkness of the night sky?

1. A star’s solid angle on Earth’s surface is
very small, due to its distance away from us.
2. Dark matter between the stars and Earth
absorbs the star’s light.
3. The universe is expanding and the frequency spectrum of the light from stars moving away from Earth is “red-shifted” and diminished in intensity.
4. The universe is young (only 15 billion
years old) and many stars (if there are any)
are so far away that their light has not had
time to reach us.
5. The universe is permeated with electromagnetic waves, but very little is in the visible
part of the spectrum.

The answer is:
2. Dark matter between stars and Earth
==> Dark matter does not absorb light, it diffracts it due to gravitational lensing effect. The light still goes past.

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4 is also wrong. The star's light has reached us. That is why we can see the star.