Which vitamin is essential for the conversion of tryptophan to niacin in the body?

A Vitamin B6
B Vitamin B12
C Vitamin C
D Vitamin B3
Vitamin B3, also known as niacin, can be synthesized from tryptophan in the body, and this process requires other B vitamins, but the question focuses on the direct involvement of Vitamin B3 itself.
Biochemistry textbooks
Vitamins Nutrition Niacin and Tryptophan Metabolism Medium NURSING Confidence: high