题目选项分析

As would be the case with any star of similar mass, once the Sun exhausts the hydrogen in its core, it will expand into a red giant and eventually eject its outer envelope of gases to become a white dwarf.

As in the case of any star of similar mass, once the hydrogen in the Sun's core is exhausted, it will expand into a red giant, and eventually ejecting its outer envelope of gases to become a white dwarf.