According to "Black Hole Beginnings," what causes the end of a star?

nuclei melding

gravity pushing outward

the star's center collapsing

its nuclear furnace running out of fuel

The correct answer is: its nuclear furnace running out of fuel.

Explanation:

This article provides a clear example of cause and effect structure, where we can notice that the author expresses effects and its main causes which influenced by the mentioned effects.

As an example, we could use the fact that after a certain time, a nuclear furnace of the stars runs out fuel and causes the end of a star.