I want to know the answer to the following question:
What sub-genre of hard rock does Def Leppard belong to?
All the background I'm provided with is that "Quiet Riot's album Metal Health (1983) was the first glam metal album, and arguably the first heavy metal album of any kind, to reach number one in the Billboard music charts and helped open the doors for mainstream success by subsequent bands.". Is that enough to answer the question?