**Core Concept**
The parotid duct, also known as Stensen's duct, is a structure that conveys saliva from the parotid gland to the oral cavity. It is an important anatomical feature that is often tested in medical exams.

**Why the Correct Answer is Right**
The parotid duct pierces the buccinator muscle and runs forward in the cheek, then curves upward through the masseter muscle and opens into the oral cavity near the second upper molar. This unique course allows it to deliver saliva to the mouth for food digestion and oral health. The duct's passage through the masseter muscle is a critical anatomical landmark.

**Why Each Wrong Option is Incorrect**
**Option A:** This option is not provided, however, the parotid duct does not pierce the digastric muscle, the stylohyoid ligament, or the internal carotid artery.

**Option B:** The parotid duct does not pierce the external carotid artery, but it does run close to it.

**Option C:** The parotid duct does pierce the buccinator muscle.

**Option D:** The parotid duct does pierce the masseter muscle.

**Clinical Pearl / High-Yield Fact**
The parotid duct's course through the masseter muscle is a key landmark for identifying the location of the parotid gland and its duct. This knowledge is essential for surgical procedures and anatomical identification.

**Correct Answer: C. The parotid duct does pierce the buccinator muscle.