Answer:
C) Water's original cost less Fire's recorded gain.
Step-by-step explanation:
If they were independent companies, Water and Fire should record this transaction the following way: Fire will dispose the asset and report a gain, and Water should record the asset at purchase cost.
But since Water controls Fire, they must present a consolidated balance, so no actual sale can be recorded, so Fire cannot report a gain. Water should record the asset at its original cost - Fire's gain.