Answer:
The correct answer is b.
Step-by-step explanation:
In the endocrine system, the signaling molecule or hormone is produced by a gland and discharged into the blood where it travels until it reaches certain cells distant from its place of origin on which it acts. In autocrine communication, the signal produced by a cell regulates the cell that produced it, that is, it is when the cells send messages to themselves. In autocrine signaling, a cell releases a hormone that acts on the same cell. This occurs between cells that are relatively close together and the existence of a specialized structure is not necessary, being a local communication.