Correct Option: A

Christian Neethling Barnard was a South African cardiac surgeon who performed the world’s first successful human-to-human heart transplant. Following the first successful kidney transplant in 1953, in the United States, Barnard performed the first kidney transplant in South Africa in October 1967. Barnard experimented for several years with animal heart transplants. More than 50 dogs received transplanted hearts. He performed the world’s first human heart transplant operation on 3 December 1967, in an operation assisted by his brother, Marius Barnard; the operation lasted nine hours and used a team of thirty people.