Jovian planets did not form in the inner solar system because: a. it was too hot for light-weight but abundant water, ammonia, and methane molecules to accrete into planetesimals that were sufficiently massive to gravitationally pull hydrogen and helium gas out of the solar nebula. b. it was cool enough in the inner solar system to accrete heavier metal and rock molecules into planetesimals, but since metals and rocks are significantly less abundant than water, ammonia, and methane, these planetesimals were small and not sufficiently massive to gravitationally pull hydrogen and helium out of the solar nebula.