**Core Concept**
The gastrointestinal tract (GIT) secretion is primarily controlled by the **enteric nervous system** and various hormones. The **gastrointestinal hormones** and the **autonomic nervous system** play a crucial role in regulating the secretion of digestive enzymes and fluids.

**Why the Correct Answer is Right**
Since the correct answer is not provided, I will give a general explanation. The correct answer is likely related to the **hormonal control** of GIT secretion, which involves hormones such as **gastrin**, **secretin**, and **cholecystokinin**. These hormones stimulate the secretion of digestive enzymes and fluids from the stomach, pancreas, and small intestine.

**Why Each Wrong Option is Incorrect**
**Option A:** Without the specific option, it's challenging to provide a detailed explanation. However, any option that does not involve the **enteric nervous system** or **hormonal control** is likely incorrect.
**Option B:** Similarly, without the specific option, it's difficult to provide a detailed explanation. Any option that does not involve the **autonomic nervous system** or **gastrointestinal hormones** is likely incorrect.
**Option C:** This option is also unclear without specific details. However, any option that does not involve the **regulation of digestive enzymes and fluids** is likely incorrect.
**Option D:** Without the specific option, it's challenging to provide a detailed explanation. Any option that does not involve the **integration of hormonal and nervous control** is likely incorrect.

**Clinical Pearl / High-Yield Fact**
The **enteric nervous system** is often referred to as the "little brain" of the gut, as it can function independently of the central nervous system to control digestion. Remembering the key hormones involved in GIT secretion, such as **gastrin** and **secretin**, is crucial for understanding the regulation of digestive processes.

**Correct Answer:** Correct Answer: D. Hormonal control and enteric nervous system.