The correct option is C Monkey
Rh factor is a protein substance present on the surface of red blood cells of many humans. The Rh, or rhesus factor was discovered in 1940 by K. Landsteiner and A.S. Wiener who observed that; following a series of injections of blood from a rhesus monkey into rabbits, their serum clumped the red cells of the monkey, as was to be expected, but also the red cells of about 85 percent of human beings indicating the presence of the same factor on the RBC of humans.