Scientists and astronomers have found that in galaxies with central black holes, there are also large star formations near those black holes. What has this led researches to conclude?

A. that star formations create black holes

B. that black holes and star formations are unrelated

C. that black holes and star formation are related

D. that black holes create star formations

This is for Astronomy not Physics but it didn't give me an Astronomy choice.

Athin nonconducting rod with a uniform distribution of positive charge q is bent into a circle of radius r. the central perpendicular axis through the ring is a z-axis, with the origin at the center of the ring. a) what is the magnitude of the electric field due to the rod at z = 0? n/c (b) what is the magnitude of the electric field due to the rod at z = infinity? n/c (c) in terms of r, at what positive value of z is that magnitude maximum? r (d) if r = 4.00 cm and q = 9.00 µc, what is the maximum magnitude? n/c