The correct option is
B Robert Brown in 1831
In eukaryotic cells, the nucleus is a double membrane covered protoplasmic body that contains heredity information. The nucleus was discovered by Robert Brown in 1831. With the help of grafting experiments on
Acetabularia, Hammerling in 1953 proved that nucleus is a storehouse of hereditary information.
So, the correct answer is 'Robert Brown in 1831'