The correct options are
A Neutron was discovered by Chadwick.
B Nuclear filsion was discovered by Hahn and Strassmann
D Polonium was discovered by Madam Curie
A) Neutron was discovered by Chadwick.
B) Nuclear fission was discovered by Hahn and Strassmann.
C) Polonium was discovered by Madam Curie
D) 1929 - Atkinson and Houtermans provide the first calculations of the rate of nuclear fusion in stars. 1932 - Mark Oliphant discovered helium 3 and tritium, and that heavy hydrogen nuclei could be made to react with each other. Nuclear fusion was not discovered Fermi.
So, only option D is wrong. Remaining all are correct.