All vertebrates have general sensors in their skin for touch, pressure, and pain. these are called
olfactory receptors
chemoreceptors
photoreceptors
mechanoreceptors

The right answer is D. mechanoreceptors.

Mechanoreceptors are receptors that inform the central nervous system about sensations of touch, vibration and skin tension. They are sensitive to the mechanical deformations of the skin induced by the contact of the objects. They are at the origin of the exteroceptive sensitivity epicritic touch (discriminative) and allow the exploration and analysis of the external environment. They have high sensitivity and are connected to fast-conductive large diameter myelinated fibers (type A alpha).

There are 4 main types, two in the epidermis, two in the dermis and a fifth, the hair terminals (very sensitive detection of a fleeting and light contact).

They are sensitive to:

* Touch (epicritic and protopathic tact)

* Vibration (pallaesthesia)

* Positional sensations: static position (statesthesia) and movement perception (kinesthetic): stretching and movement of joints

* Pressure (baresthesia) in the heart and blood vessels, bladder, digestive organs, teeth

stratosphere: as the altitude increases, the air temperature increases. the stratosphere has a layer of ozone, called the ozone layer. this layer absorbs most of the ultraviolet radiation from sunlight. this results in the stratosphere being warmer.