**Core Concept**
The **acinic cell tumor** is a rare type of tumor that originates from the secretory cells of the salivary glands, specifically from the **acinar cells**. This type of tumor is also known as **acinar cell carcinoma**. It is a malignant tumor that can occur in both major and minor salivary glands.

**Why the Correct Answer is Right**
The correct answer is related to the **parotid gland**, which is the largest of the salivary glands and contains a high concentration of **acinar cells**. These cells are responsible for producing **amylase**, an enzyme that breaks down starches into sugars. The **acinic cell tumor** arises from these cells and can cause symptoms such as a palpable mass in the parotid gland.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is incorrect because the **acinic cell tumor** is not typically associated with this location.
**Option B:** This option is incorrect because the **acinic cell tumor** is not typically associated with this location.
**Option C:** This option is incorrect because the **acinic cell tumor** is not typically associated with this location.

**Clinical Pearl / High-Yield Fact**
The **acinic cell tumor** is a rare tumor that can be difficult to diagnose, but it is important to consider it in the differential diagnosis of salivary gland tumors. A key feature of this tumor is its potential to cause **metastasis**, making early diagnosis and treatment crucial.

**Correct Answer:** D. Parotid gland