Final answer:
Most stars that are less massive than the Sun eventually form white dwarfs, which are dense remnants supported by electron degeneracy pressure after they have exhausted their nuclear fuel and shed much of their mass.
Step-by-step explanation:
The type of compact object that most stars smaller than the Sun form after they "die" is a) White dwarfs.
During the late stages of stellar evolution, stars that are less massive than the Sun tend to shed their outer layers. Stars with original masses up to about 8 solar masses (Msun) can lose enough mass to fall below the Chandrasekhar limit of approximately 1.4 solar masses. When these stars exhaust their nuclear fuel, their cores become compressed until they are supported by the degeneracy pressure exerted by electrons. This forms a compact, dense remnant known as a white dwarf, which is primarily composed of carbon, oxygen, and neon. Over time, white dwarfs will further cool and fade away into black dwarfs, although the universe is not old enough for any black dwarfs to exist yet.