Olfactory receptors are the type of:

Explanation

Smell depends on molecules dissolving in the mucus and binding receptor proteins in the nasal epithelium, so olfactory receptors respond to chemicals and are chemoreceptors, as are the taste buds. Photoreceptors detect light in the retina and mechanoreceptors detect pressure, touch and sound. Classifying a receptor means asking which form of energy or signal it transduces.