The distinct golden colour in transgenic Golden rice is due to presence of: (A) Riboflavin, (B) β-carotene, (C) Vitamin B12, (D) Xanthopyll
Answer is B. Golden rice:
Variety of rice produced through genetic engineering to boisynthesize beta carotene, a precursor of vitamin A.
The distinct golden colour is due to the beta carotene content.
It is indented to produce a fortified food to be grown and consumed in areas with a shortage of dietary vitamin A. 
Golden rice differs from its parenteral strain by the addition of three beta carotene biosynthesis gene.