According to paragraph 1, which of the following best describes the "nebular hypothesis?" A. Our solar system formed from a large cloud consisting mostly of hydrogen and helium and of small amounts of other elements. B. Our solar system formed from gases and heavier elements thrown off by the Sun as it rotated in the center of the nebular cloud. C. The primordial matter that evolved into our solar system consisted mostly of familiar elements such as oxygen, carbon, and nitrogen. D. A cloud of dust and gases gathered into a rotating nebula composed mostly of the rocky materials seen on Earth today.