Explanation:

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

- Altercation refers to a noisy or heated argument or disagreement.

- ?? Correct Answer as it captures the essence of a dispute escalating to physical confrontation.

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

- Match usually refers to a game or competition.

- Unlikely to escalate to a fight without more context.

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

- Contest signifies a competition or challenge.

- Does not imply conflict by itself.

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

- Race is a competition of speed.

- Typically non-confrontational.