Which One of the Following Statements About Fission and Fusion $\Delta$

Which one of the following statements about fission and fusion is false?

A) Fission occurs among the heaviest isotopes, whereas fusion occurs more readily for light isotopes.
B) For a fission reaction the mass defect ( $\Delta$ m) is negative, whereas for fusion $\Delta$ m is positive.
C) In order for fusion reactions to occur, temperatures must be in the millions of degrees.
D) The fission of Pu-239 atoms produces a great number of isotopes of a large number of elements.
E) Neutron-induced fission processes can occur at room temperature, rather than at millions of degrees.