Can someone answer this

Each element absorbs light at specific wavelengths unique to that atom. When astronomers look at an object's spectrum, they can determine its composition based on these wavelengths. The most common method astronomers use to determine the composition of stars, planets, and other objects is spectroscopy.

I would say "A"

did u get the answer? /? ? / me

it takes hundreds of years to become stable.

if you have another question lmk.