Final answer:
The skin is the body's largest organ and it is part of the integumentary system, which also includes hair and nails. It has multiple vital functions and contains numerous blood vessels, sweat glands, and nerve endings within its 2 mm thickness.The correct option is a.
Step-by-step explanation:
The largest organ of the body is the skin. It is a part of the integumentary system which also includes hair and nails. The skin not only serves as the body's outer covering but also performs various vital functions such as regulation of body temperature, protection from external elements, and sensation. The skin's complexity is evident by its various components, which include blood vessels, sweat glands, nerve endings, and pigment-producing cells. It's also noteworthy that the skin's thickness is quite small, approximately 2 mm, which is roughly as thick as the cover of a book.
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