How Do Astronomers Know That the Sun (And Our Solar

How do astronomers know that the Sun (and our Solar System) formed from the remnants of other stars?

A) The Sun acts like a low-mass star and a high-mass star at the same time.
B) Elements heavier than hydrogen and helium must have formed within other stars and then were ejected into space by supernovae.
C) Radioactive carbon could only form in the core of a high-mass star.
D) Jupiter shows signs of having been a main-sequence star at one point.
E) Evidence shows that the asteroids and comets must have formed around stars with different spectral types than the Sun.