Question

which evidence supports the big bang theory?
planetesimals form in debris disks
most galaxies are moving toward us.
uniform background radiation is detected in every direction
galaxies spin faster than they should based on visible matter

Explanation:

The cosmic microwave background radiation, which is a form of uniform background radiation detected in every direction, is one of the key pieces of evidence for the Big - Bang theory. It is the afterglow of the hot, early universe. Planetesimals forming in debris disks relates to planet - formation, most galaxies moving toward us is incorrect as most are moving away (Hubble's law), and galaxies spinning faster than expected due to visible matter is evidence for dark matter.

Answer:

Uniform background radiation is detected in every direction.