**Core Concept**
The lymphatic drainage of the glans penis is an essential aspect of understanding the anatomy and physiology of the male genitalia. The lymphatic system plays a crucial role in draining excess fluids, proteins, and waste products from the body, including the glans penis.

**Why the Correct Answer is Right**
The lymph from the glans penis drains into the deep inguinal lymph nodes, which are located in the inguinal canal. This is due to the fact that the glans penis is a part of the external genitalia and receives lymphatic drainage from the superficial inguinal lymph nodes. The deep inguinal lymph nodes then drain into the external iliac lymph nodes, which ultimately drain into the lumbar lymph nodes and the thoracic duct. The thoracic duct then drains into the bloodstream through the jugular and subclavian veins.

**Why Each Wrong Option is Incorrect**
* **Option A:** The superficial inguinal lymph nodes primarily drain the skin of the lower limb, including the thigh and the lower part of the abdomen, but not the glans penis.
* **Option B:** The internal iliac lymph nodes receive lymphatic drainage from the pelvic organs, including the bladder, prostate, and seminal vesicles, but not directly from the glans penis.
* **Option C:** The lumbar lymph nodes receive lymphatic drainage from the abdominal organs, including the kidneys, adrenal glands, and pancreas, but not directly from the glans penis.

**Clinical Pearl / High-Yield Fact**
It's essential to remember that the lymphatic drainage of the external genitalia, including the glans penis, is primarily through the superficial and deep inguinal lymph nodes. This knowledge is crucial in understanding the spread of infections and malignancies in this region.

**Correct Answer:** D