Why Do the Outer Giant Planets Have Massive Gaseous Atmospheres

Multiple Choice

Why do the outer giant planets have massive gaseous atmospheres of hydrogen and helium whereas the inner planets do not?

A) These gases were more abundant in the outer regions of the accretion disk where the outer planets formed.
B) The outer planets grew massive quickly enough to hold on to these gases through gravity before the solar wind dispersed the accretion disk.
C) The inner planets "used up" all of the rocky materials.
D) Frequent early collisions by comets with the inner planets caused most of their original atmospheres to dissipate.
E) They were most likely captured by the Sun after our Solar System formed.