Nancy Nelson Pays $200,000 for Land and a Building in a Single

Nancy Nelson pays $200,000 for land and a building in a single transaction. At the time of the purchase, the land and building were appraised at $120,000 and $180,000, respectively. Nancy's depreciable basis in the building is:

A) $0.
B) $100,000.
C) $80,000.
D) $120,000.
E) $180,000.