Any person who sells, or exposes for sale, or has in his possession for sale or for any purpose of trade or production of any variety to which any false denomination is applied or to which an indication of the country or place in which such variety was made or produced or the name and address of the breeder of such variety registered under this Act has been falsely made, shall, unless he proves—

(a) that having taken all reasonable precautions against committing an offence against this section, he had at the time of commission of the alleged offence no reason to suspect the genuineness of the denomination of such variety or that any offence had been committed in respect of indication of the country or place in which such variety registered under this Act, was made or produced or the name and address of the breeder of such variety,

(b) that, on demand by or on behalf of the prosecutor, he gave all the information in his possession with respect to the person from whom he obtained such variety; or

(c) that otherwise he had acted innocently,