According to the nebular hypothesis, what likely triggered the collapse of the solar system's progenitor cloud?

Answer

The shockwave of a nearby supernova

The widely accepted nebular hypothesis suggests that the vast, rotating cloud of gas and dust began to contract after being triggered, most likely by a shockwave emanating from a supernova explosion nearby.

According to the nebular hypothesis, what likely triggered the collapse of the solar system's progenitor cloud?
astronomyEarthsolar systemplanet formationsolar nebula