D. As used in this section:

1. "Expenses of an emergency response" means reasonable costs directly incurred by a public agency, for-profit entity or not-for-profit entity that makes an appropriate emergency response to an accident, including the costs of providing police, fire fighting, rescue and emergency medical services at the scene of an accident and the salaries of the persons who respond to the accident but excluding charges assessed by an ambulance service that is regulated pursuant to title 36, chapter 21.1, article 2.

2. "Public agency" means this state and any city, county, municipal corporation, district or other public authority that is located in whole or in part in this state and that provides police, fire fighting, medical or other emergency services.