Schwerin Corporation reports the following on its $2022$ financial statements.

From statement of cash flows

Cash proceeds from sale of equipment $$210$ million

Cash outflow from purchase of equipment $125$ million

Depreciation $30$ million

Gain from sale of equipment $60$ million

The net book value of equipment sold was:

A$.$

$$210$ million

B$.$

$$125$ million

C$.$

$$150$ million

D$.$

$$120$ million