What type of defense is characterized by a party's admission of facts but argues that circumstances justify their actions?

An affirmative defense is a legal strategy used by a party in a case where they acknowledge the facts presented by the opposing side but seek to justify their actions based on a specific set of circumstances. This signifies that the party is not contesting the facts but is offering an explanation that absolves them of liability or leads to a different legal outcome.

For example, in a situation where a defendant admits to committing an act but claims it was necessary to prevent greater harm, this would fall under the umbrella of an affirmative defense. It allows the party to introduce evidence that supports their justification for the actions taken.

The other options do not fit the definition as neatly. Ordinary defenses typically involve disputing the facts or arguing that the allegations do not hold up under scrutiny. Reasonableness is a standard that may inform various defenses but does not specifically categorize the type of justification being claimed. Necessity relates closely to affirmative defenses but is a specific instance where actions were taken to prevent significant harm or danger. Nonetheless, the broader category that encompasses various justifications, including necessity, is the affirmative defense, making it the best answer.