Final answer:
Autocrine signaling functions by enabling cells to act on themselves to regulate cellular activity, essential for maintaining homeostasis.
Step-by-step explanation:
Autocrine substances are crucial to maintaining homeostasis within the body. The correct answer to how these substances function is b) They act on the same cell that produced them to regulate cellular activity. Autocrine signaling involves a cell producing a signal molecule that binds to receptors on its own surface. This initiates a signaling cascade within the same cell, leading to alterations in cellular function which can ensure proper cell development, regulate pain sensation and inflammatory responses, and even trigger programmed cell death if the cell is compromised. Essentially, through autocrine signaling, cells can self-regulate and maintain internal stability, which is a key aspect of maintaining homeostasis.