What is the origin of all stars?

supernova
dwarfs
protostars
nebulae

It is D. nebulae

I just took the quiz and this was right

The correct answer is option D, Nebulae

Reason –

Nebuale is the first stage of star formation. At this stage, region of high density condenses to form massive globules of gas and dust which later on contracts owing to its gravity.  

The second stage of star formation is the protostars stage, in which the condensing mass starts heating up and glowing.  

Dwarf stage comes at a very later stage of star formation in which the inner core of the star become white as its starts dimming and cooling off.  

Supernova stage occurs after the death of stars.  

answer; /// i believe the correct answer is (reactants);

when you breathe in, or inhale, your diaphragm contracts (tightens) and moves downward. this increases the space in your chest cavity, into which your lungs expand. the intercostal muscles between your ribs also enlarge the chest cavity. they contract to pull your rib cage both upward and outward when you inhale.