The correct answer is C, as digestion is not a function of the skin. The primary functions of the skin include protection, absorption, and thermoregulation.
To elaborate, the skin acts as a barrier that protects the underlying tissues from harmful substances, pathogens, and physical injuries. Additionally, it plays a role in absorption, particularly with substances that can penetrate the skin, such as certain medications and topical products.
Thermoregulation is another essential function of the skin, helping to maintain the body’s internal temperature. The skin achieves this through mechanisms like sweating and the dilation or constriction of blood vessels, which help to dissipate or conserve heat.
Digestive processes occur in the digestive system, involving organs specific to processing food and absorbing nutrients. The skin does not participate in digestion, which distinguishes it from the other functions that are directly related to the skin's primary roles.