Any district school board, school athletic association, or school may formulate, conduct, and purchase a plan or method of insuring, or may self-insure, school students against injury sustained by reason of such students engaging and participating in the athletic activities conducted or sponsored by the district school board, association, or school in which such students are enrolled. A district school board, school athletic association, or school may add a surcharge to the fee charged for admission to athletic events as a means of producing revenue to purchase such insurance or to provide self-insurance. Any district school board may pay for all or part of such plan or method of insurance or self-insurance from available district school board funds.