Which bear describes a chain reaction associated with nuclear reaction

If your choices are the following: A. Neutrons released during a fusion reaction cause other nuclei to fuse.

B. Neutrons released during a fission reaction cause other nuclei to split.

C. Helium nuclei released during a fission reaction cause other nuclei to split.

D. Helium nuclei released during a fusion reaction cause other nuclei to fuse.

Then the answer is B. In fission, the nuclei is splitted and releases neutrons causing another chemical to form.