What are the spiral arms of the Milky Way made of?

AOlder stars and comets
BVariable stars
CAsteroids and comets
DYounger stars and gaseous nebulae

Verified Answer :

W0lf93

The spiral arms of the Milky Way are made of younger stars and gaseous nebulae. There are four spiral arms within the Milky Way galactic disc that start at the galaxy's center. The sun is five to 30 parsecs away from the center of the galactic disk.

younger stars and gaseous nebulae d is the corrcet answer