Which of the Following Important Components Does a Planetary Nebula

Which of the following important components does a planetary nebula contribute to the interstellar medium?

A) nuclei of elements like carbon, nitrogen, and oxygen, which are major components of planets such as our own
B) UV light that photoionizes hydrogen, which produces the red Balmer- light we see in emission nebulae
C) rotational motion from the original star, which serves to concentrate interstellar matter into new stars and planetary systems
D) new hydrogen nuclei, replenishing those which are lost when stars form