Which of the following is a Noun?

- Carelessness is a noun meaning failure to give sufficient attention to avoiding harm or errors; negligence.
- Careless is an adjective which means not giving sufficient attention or thought to avoid harm or errors.
- Carelessly is an adverb which means in a casual or reckless way; inattentively.
- caring is an adjective which means kind, helpful and showing that you care about other people.