Question

fission and fusion are alike in many ways. however, one difference is
a fusion forms dangerous nuclear waste that is difficult to dispose whereas fission does not.
b fission is a controllable chain reaction and fusion is not.
c fusion results in a greater product mass whereas fission does not.
d raw materials for fission are cheaper and easy to get.

Explanation:

Fission is a controllable chain - reaction used in nuclear power plants, while fusion is currently not controllable on Earth in a practical, long - term, and stable way for power generation. Fusion produces little to no long - lived nuclear waste compared to fission. In both processes, mass is converted to energy according to Einstein's $E = mc^{2}$, and it's not clear - cut that fusion results in a greater product mass. Also, the raw materials for fusion (like hydrogen isotopes) are abundant, but uranium for fission is not necessarily cheaper or easier to obtain.

Answer:

B. Fission is a controllable chain reaction and fusion is not.