Which of the following compound contains cobalt

Vitamin B₁₂ is one of the following compounds that contain cobalt.
Vitamin B₁₂ is also known as cobalamin, it contains cobalt.
It plays an essential role in red blood cell formation, cell metabolism, nerve function, and the production of DNA, the molecules inside cells that carry genetic information.
Food sources of vitamin B₁₂ include poultry, meat, fish and dairy products.