The correct answer is negligent.
In tort law, negligence refers to when a person or organization unintentionally causes harm or injury to others. For instance, if a day care facility has rotting mold (that the staff is not aware of) that affects the children's health and makes them ill, it is a negligence on the part of the day care center. Another instance of negligence is having your neighbor's dog escape their house (without your neighbor's knowledge) and then proceed to enter your house to attack your cat.