The correct option is C Receptor
Hormones are the special chemical messenger secreted by endocrine glands. They are produced by organ and shows the effects on other organs (target organ). They are carried to the target organ by blood. Hormone induces their effect by binding to specific proteins, these protein are called as receptors. These receptors are membrane-bound or intracellular. The receptor is specific to a particular hormone. Thus, the correct answer is option C.