Why Is It Not Possible to Look All the Way $\gt$

Multiple Choice

Why is it not possible to look all the way back to the Big Bang itself?

A) Photons are not produced until the stars begin to shine at a redshift of z 20.
B) From redshifts of z=0 to 100, photons are gravitationally lensed by the dark matter in the universe.
C) At redshifts of z $\gt$ 1,000, most of the photons are blocked by large amounts of cold gas and dust.
D) For redshifts of z $\gt$ 1,000, photons cannot travel freely because they easily interact with individual protons and electrons in the universe.
E) Photons from the Big Bang would be so strongly redshifted that we could never detect them.