The correct option is B heroically
'Adverb' is a word that is used to change or qualify the meaning of an adjective, a verb, a clause or another adverb.
In the given sentence, the verb is 'fought'.
Option B - 'heroically' is an adverb which describes the verb 'fought'.
On the other hand, Option A - 'heroic' is an adjective which can modify a noun, but not the verb.
Option C - 'heroism' is noun form which cannot modify another verb.
Therefore, the suitable option to complete the given sentence is Option B - heroically'.
The completed sentence thus becomes: The firemen at the Taj Hotel fought heroically to put out the fire.