Which of the following is not classified as a private insurer?

Self-insurers are individuals or organizations that assume the financial risk of loss instead of purchasing an insurance policy from a private insurer. By self-insuring, they set aside funds to cover potential losses rather than transferring that risk to another party through a formal insurance arrangement. This distinguishes them from stock companies, mutual companies, and noncommercial organizations, all of which provide insurance coverage and are classified as private insurers. Stock companies and mutual companies are traditional insurers that operate for profit (stock) or on a mutual basis for their policyholders (mutual), whereas noncommercial organizations offer insurance products typically on a nonprofit basis. Self-insurers operate independently of the insurance market, aligning them outside the classification of private insurers.