Final answer:
A homicide occurring by accident while performing a lawful act with ordinary caution and no illegal intent is considered excusable. This classification is used when the action leading to death was not intended to harm and was within legal boundaries.
Step-by-step explanation:
A homicide that occurs "when committed by accident and misfortune, or in doing any other lawful act by lawful means, with usual and ordinary caution and without any unlawful intent" is considered B) excusable. This classification acknowledges that the killing was unintentional, rather than a result of negligence or a criminal act. In such cases, the person responsible may not be held legally culpable because there was no intention to harm (i.e., the absence of mens rea) and all actions taken were within the bounds of the law and with due caution.