challenge: What event occurred in October 1800 that led to significant changes in the area of Abernant?
  
  A. The founding of the Abernant Ironworks
  B. The diversion of water courses for the Abernant Ironworks
  C. The signing of a lease for the lands and mines at Abernant y Wenallt
  D. The construction of the first workers houses
  Answer: 