In which sentence from Black hole beginnings is a cause underlined

As per the question, option B i. e. 'As the star material gathers, its inward pressure grows' involves a cause ('the material gathers') underlined that leads to the effect 'growing of inward pressure.' This sentence reflects a cause-and-effect structure as it states an important fact about the beginnings of the Blackhole by displaying the cause or reason i. e. 'gathering of star material' which resulted in the 'growth of inward pressure' that would provide the readers with a better understanding and comprehension. Thus, option B is the correct answer.