Fill in the blank with the correct option.

A small _________ between two children ended up as a group fight.

altercation

The correct answer is Option (1) - altercation

Here's why:

Altercation : means a noisy argument or disagreement. This aligns well with the situation of a small disagreement escalating into a bigger fight.
Match : refers to a competition or game. It doesn't necessarily imply an argument.
Contest : can be a competition, but it's broader and doesn't capture the initial argument between the two children.
Race : refers to a competition of speed. It's not relevant to the situation.

Therefore, "altercation" is the most fitting word to describe the small disagreement that led to the fight.