In trials under this Act, it may be presumed, unless and until the contrary is proved, that the accused has committed an offence under Chapter IV in respect of-
(a) any narcotic drug or psychotropic substance;
(b) any opium poppy, cannabis plant or coca plant growing on any land which he has cultivated;
(c) any apparatus specially designed or any group of utensils specially adopted for the manufacture of any narcotic drug or psychotropic substance; or
(d) any materials which have undergone any process towards the manufacture of a narcotic drug or psychotropic substance, or any residue left of the materials from which any narcotic drug or psychotropic substance has been manufactured, for the possession of which he fails to account satisfactorily.