Question

when the core temperature of a main sequence star reaches 100 million k, helium fuses to form heavier elements, and it swells to a larger size, becoming a
select one
a. black hole
b. giant star
c. hertzsprung - russell diagram
d. main sequence star
e. nebula
f. planetary nebula
g. protostar
h. star
i. supernova
j. white dwarf
word is used only once.
ess night and look up into the universe, you can milky way and beyond. some of these lights are anets and moons. most of them come from large ravity, with intensely hot cores burning from

Explanation:

A main sequence star swells to a larger size when its core temperature reaches 100 million K (enabling helium fusion), transitioning into a giant star. Other options: black hole is a final collapse state, Hertzsprung-Russell diagram is a star classification tool, main sequence star is the initial state, nebula/protostar are early formation stages, supernova is an explosion, white dwarf is a remnant.

Answer:

B. giant star