Except as provided in subsections (c) and (d) of this section, each retail service station in the State: shall be operated by a retail service station dealer; and may not be operated by a producer or refiner of motor fuel: with a commissioned agent, company personnel, or a subsidiary company; or under a contract with a person who manages the station on a fee arrangement with the producer or refiner. This section does not apply to facilities that an agricultural cooperative association owns and operates if: the agricultural cooperative association is certified by a bank for cooperatives to be eligible to borrow from the bank under Subchapter III of the federal Farm Credit Act of 1971; the certification is submitted to the Comptroller with the application for registration of a retail service station dealer under this subtitle; the agricultural cooperative association owns the property on which the facilities are located; and on the property, the agricultural cooperative association, as part of its business, sells or provides farm supplies or farm business services or distributes motor fuel in bulk to farmers on farms. A retail service station shall be exempt from subsection (a) of this section for a fiscal year that starts July 1, if: on January 1, 1979, the station was operated by a subsidiary of a producer or refiner of motor fuel; and the gross revenues of the subsidiary from the sale of motor fuel in the State for the preceding calendar year is less than 2% of the gross revenues of the subsidiary from all retail operations in the State for the preceding calendar year. If a dealer has previously operated a retail service station, the Comptroller may adopt regulations that define the circumstances in which a producer or refiner temporarily may operate the station.