If a Galaxy Had No Dark Matter,how Would the Velocity

If a galaxy had no dark matter,how would the velocity (v) of a star that orbited far outside the visible extent of the galaxy depend on its distance (r) from the center of the galaxy?

A) ν ∝ r⁻²
B) ν ∝ r⁻¹
C) ν ∝
D) ν ∝ r
E) ν ∝ r²