How do dying stars contribute to the formation of planets?

Question

They emit helium gas that attaches to nearby planets.
They remove low-mass elements from the planets’ crust.
They cause nuclear fusion inside the inner core of planets.
They produce heavy elements such as iron and gold.

Answer 1

If the question refers to supernovae, they produce the heavy elements and eject them into the interstellar medium.  Eventually, these elements are drawn to protoplanets.