As used in the Gross Receipts Tax Registration Act:
A. "department" means the taxation and revenue department, the secretary of taxation and revenue or any employee of the department exercising authority lawfully delegated to that employee by the secretary;
B. "person" means any individual, estate, trust, receiver, cooperative association, club, corporation, company, firm, partnership, joint venture, syndicate or other entity; and
C. "state" means any state agency, department or office that has authority to contract in the name of the state or to make payments from state funds.