Which one of the following is not one of the four major features of the solar system?

a. Planets fall into two major categories (terrestrial and jovian).
b. Large bodies in the solar system have orderly motions.
c. Several exceptions to the general trends stand out.
d. Swarms of asteroids and comets populate the solar system.
e. The solar system contains eight planets plus dwarf planets (such as Ceres, Pluto, and Eris).