**Core Concept**
Meissner's and Auerbach's plexuses are two types of submucosal plexuses found in the gastrointestinal tract. They are part of the enteric nervous system, which plays a crucial role in regulating gut motility, secretion, and blood flow.

**Why the Correct Answer is Right**
Meissner's and Auerbach's plexuses are derived from the neural crest, specifically from the ectodermal cells that migrate to the developing gastrointestinal tract during embryogenesis. These plexuses are responsible for the intrinsic innervation of the gut, allowing for local regulation of gut functions without direct input from the central nervous system. The neural crest cells that give rise to these plexuses differentiate into various types of neurons and glial cells, forming a complex network that coordinates gut function.

**Why Each Wrong Option is Incorrect**
**Option A:** Incorrect because Meissner's and Auerbach's plexuses are not derived from the epidermis.
**Option B:** Incorrect because these plexuses are not formed from the mesoderm, which gives rise to smooth muscle, blood vessels, and connective tissue in the gut.
**Option C:** Incorrect because the enteric nervous system, including Meissner's and Auerbach's plexuses, is not derived from the endoderm, which gives rise to the lining of the gut.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the enteric nervous system is often referred to as the "little brain" of the gut, highlighting its significant role in regulating gut functions and its potential involvement in various gastrointestinal disorders.

**Correct Answer:** D.