**Core Concept**
The procedure involves the surgical excision of a single lactiferous duct, which is a part of the mammary gland responsible for milk secretion. This procedure is typically performed to diagnose or treat conditions such as galactorrhea, nipple discharge, or breast pain.

**Why the Correct Answer is Right**
The correct procedure is a microdochectomy, which is a surgical excision of a single lactiferous duct. This procedure is usually performed under local anesthesia and involves the removal of the affected duct to diagnose the underlying cause of the nipple discharge or other symptoms. The lactiferous ducts are connected to the nipple via the subareolar ducts, and the removal of a single duct does not typically affect the overall function of the breast.

**Why Each Wrong Option is Incorrect**
* **Option A:** This option is incorrect because a ductography is a radiologic procedure that involves injecting a contrast agent into the breast ducts to visualize the ductal system, but it does not involve surgical excision.
* **Option B:** This option is incorrect because a ductal lavage is a procedure that involves flushing the breast ducts with a saline solution to collect cells for cytologic examination, but it does not involve surgical excision.
* **Option C:** This option is incorrect because a biopsy of the breast tissue may be performed to diagnose breast cancer or other conditions, but it is not specifically a procedure for excising a single lactiferous duct.

**Clinical Pearl / High-Yield Fact**
A microdochectomy is a diagnostic and therapeutic procedure that can help identify the underlying cause of nipple discharge or other symptoms, and it is usually performed under local anesthesia to minimize discomfort.

**Correct Answer: D. Microdochectomy**