Answer:
a. Material from previous stars
Step-by-step explanation:
Solar nebula was a molecular cloud, composed of dust and gases from which the sun and planets were born. The solar nebula material came from the material from the previous stars. When a star dies, it expels out most of its mass and from this material, nebula is formed from which new stars and planets form.
Solar wind is composed of high speed charged particles emitting out from the sun.
Terrestrial planets have rocky surface.