Final answer:
An apocrine gland is NOT a sensory receptor of the skin.
Step-by-step explanation:
The correct answer is B. an apocrine gland. The sensory receptors of the skin mentioned in the options are Meissner corpuscles, root hair plexus, and nociceptors, which are all involved in sensing touch, hair movement, and pain, respectively. On the other hand, apocrine glands are not sensory receptors, but rather a type of sweat gland that produces a thick and odorous secretion.