Read this and answer the question. If the question is unanswerable, say "unanswerable".

The house scene in cities such as Birmingham, Leeds, Sheffield and London were also provided with many underground Pirate Radio stations and DJs alike which helped bolster an already contagious, but otherwise ignored by the mainstream, music genre. The earliest and influential UK house and techno record labels such as Warp Records and Network Records (otherwise known as Kool Kat records) helped introduce American and later Italian dance music to Britain as well as promoting select UK dance music acts.

What were the earliest and most influential record labels in Sheffield house music?
unanswerable