The First Stars Formed About 300 Million Years After Big

The first stars formed about 300 million years after Big Bang in the most massive nebulae because ________.

A) only the massive nebulae had the material needed to make stars
B) it took that long for enough matter to form to make a star
C) the massive nebulae had enough gravity to attract star material early in the history of the universe
D) the massive nebulae had enough gravity to collapse and condense
E) all of the nebulae at that time were massive and it was not until much later that smaller nebulae formed