Schwerin Corporation Reports the Following on Its 2005 Financial Statements

Schwerin Corporation reports the following on its 2005 financial statements. $\begin{array}{lr}&2004&2005\\\text { From statement of cash flows: }\\\text { Cash proceeds from sale of equipment } && \$ 100 \text { million } \\\text { Cash outflow for purchase of equipment } && 170 \text { million } \\\text { Depreciation } && 50 \text { million } \\\text { Gain from sale of equipment } && 40 \text { million }\end{array}$
-The net book value of equipment sold was:

A) $120 million
B) $100 million
C) $80 million
D) $60 million