The correct option is B 1900
Gregor Johann Mendel (1822-84) is known as Father of Genetics. Mendels work remained un-noticed and unappreciated for some 34 years. In 1900, three workers independently rediscovered the principles of heredity already worked out by Mendel. They were Hugo de Vries of Holland, Carl Correns of Germany and Erich von Tschermak of Austria.