Final answer:
The correct answer is b) Argument, as 'altercation' refers to a heated or angry dispute, closely aligned with the concept of an argument.
Step-by-step explanation:
The word that most nearly defines the underlined word in the sentence 'The two got into an altercation.' is b) Argument. An altercation refers to a heated or angry dispute, which is essentially an argument, not merely a conversation or an agreement, and certainly not a celebration.
An altercation implies a level of contention and disagreement that fits the context of an argument.
The word 'altercation' in the sentence 'The two got into an altercation' most nearly defines an argument. In this context, an altercation refers to a heated disagreement or quarrel between two people. It implies that there was conflict or discord between the individuals.