The correct option is B Receptors
Nose is the sense organ of smell. It has a pair of nostrils which open into the nasal cavity. The wall of the nasal cavity is lined by epithelial cells with smell receptors. They are connected to the sensory nerve of the nose called olfactory nerve which carries the smell impulses to the olfactory centre of the cerebrum. Molecules escaping from the object are carried into the nose through the inhaled air. On reaching the olfactory epithelium, they get dissolved in the mucus and stimulate the olfactory receptors. This stimulation in the form of chemical impulses reaches the olfactory centre of the cerebrum where they are interpreted and the smell is identified.