Both the teams played the game fairly.

The correct answer is option -B

Here,`fair' is an adjective which qualifies the noun `game'.

Usage of `fairly' is wrong here.

Fairly - is an adverb which will qualify verb `played'.

Since in sentence,`the game -noun is used.

To qualify that we will use adjective.

If we look at the context/meaning usage of Adjective `fair' is correct.

Ex- Both the teams played fairly.

Here it qualifies verb,so we use fairly (adverb)

Meaning-both the teams played in a fair manner.

Ex- Both the teams played a fair game.

Meaning -both the teams played a good,pure game.(no cheating,breaking of rules etc).