Which of the following is NOT a part of a spider's mouthparts?

Cerci are not part of a spider's mouthparts; they are appendages found in some arthropods, such as insects and certain crustaceans, used primarily for sensory functions or as a means of reproduction. In contrast, the other terms mentioned relate directly to the mouthparts of spiders.

Chelicerae are the jaw-like structures that spiders use for grasping and tearing their prey, often equipped with fangs that can inject venom. Pedipalps, which resemble small legs, have dual functions: they assist with feeding as well as playing a role in sensation and reproduction. Spinnerets are specialized structures that produce silk, crucial for web-making, wrapping prey, and other purposes. Thus, while the first three terms are integral to a spider's feeding and reproductive mechanisms, cerci do not belong to this group, highlighting their distinction as non-mouthpart appendages.