The answer is letter
A.
<span>
Dead cells can be
found on the surface of the skin. This is because every day the skin sheds dead
cells that come from the epidermis which is usually caused by sweat. The
epidermis is the outermost layer of the skin which acts out as the barrier of
the body against the environment. It prevents infections by protecting the skin
from pathogens that may enter the system and it regulates the amount of water
that the body releases into the atmosphere in the form of sweat. </span>
<span>Exposure to cigarette smoke mostly is the case</span>
