**Core Concept**
Endogenous pigmentation of teeth refers to the deposition of chromogens within the tooth structure, resulting in discoloration. This can be caused by various factors, including genetic conditions, infections, and metabolic disorders.

**Why the Correct Answer is Right**
Vitamin B deficiency is not directly associated with endogenous pigmentation of teeth. However, deficiencies in other B vitamins, such as riboflavin (B2) and niacin (B3), can lead to oral manifestations like angular cheilitis and mucosal lesions. Vitamin B deficiency itself is not a known cause of tooth pigmentation. In contrast, tetracycline can bind to calcium ions in developing teeth, leading to brown or gray discoloration. Fetal jaundice, caused by elevated bilirubin levels, can result in yellow or brown pigmentation of teeth due to the deposition of bilirubin. Erythroblastosis fetalis, a condition characterized by hemolytic disease of the newborn, can also cause tooth discoloration due to the breakdown of red blood cells.

**Why Each Wrong Option is Incorrect**
**Option A:** Tetracycline is a well-established cause of endogenous pigmentation of teeth, particularly in children whose teeth are still developing.
**Option B:** Fetal jaundice can lead to the deposition of bilirubin in teeth, resulting in yellow or brown pigmentation.
**Option C:** Erythroblastosis fetalis can cause tooth discoloration due to the breakdown of red blood cells and subsequent deposition of heme pigments.

**Clinical Pearl / High-Yield Fact**
It's essential to note that tetracycline-induced tooth discoloration can be prevented by avoiding the use of tetracycline in children under 8 years old, during tooth development.

**✓ Correct Answer: D. Vitamin B deficiency**