As a solar type star is running out of nuclear fuel for the final time, it casts off its outer layers into an expanding cloud of gas surrounding the star's collapsing core. Briefly, the cloud of gas forms a glowing nebula around the hot core. This nebula is called...
a) A supernova remnant
b) A planetary nebula
c) A Bok globule
d) A asymptotic giant nebula (AGN)