What elements do low-mass stars like the Sun primarily enrich the interstellar medium with upon death?

Answer

Carbon and nitrogen (lighter elements from hydrogen/helium burning).

Low-mass stars gently shed their outer layers as planetary nebulae, enriching the interstellar medium mostly with the lighter elements created during their hydrogen and helium burning phases, such as carbon and nitrogen.

What elements do low-mass stars like the Sun primarily enrich the interstellar medium with upon death?
ElementstellarstarFusionnucleosynthesis