Final answer:
The Milky Way's rotation curve is consistent with a flat rotation curve rather than a Keplerian one, indicating the presence of dark matter and a different mass distribution than that found in the solar system according to Kepler's laws. Option B is correct.
Step-by-step explanation:
The rotation curve of our galaxy, the Milky Way, is more consistent with a flat rotation curve than with a Keplerian one. Observations reveal that the orbital velocities of stars and gas in the outer regions of the galaxy do not decrease substantially with increasing distance from the center, as would be expected under Keplerian dynamics.
Instead, they remain relatively constant or even increase slightly, which suggests the presence of significant amounts of dark matter in the galaxy beyond the visible stars and gas.
In a Keplerian rotation curve, which reflects the motion of planets in the solar system, the orbital velocity drops off with the square root of the distance from the central mass.
This is based on Kepler's laws of planetary motion, which describe the orbits of the planets around the Sun. However, the Milky Way's rotation curve remains flat at larger radii, indicating that most of its mass is not concentrated toward the center, contrary to the mass distribution in the solar system.