nuclear fission because an atom is splitting into two fragments\nnuclear fusion because the products that…

Brief Explanations:

Nuclear fusion is the process where atomic nuclei combine to form a heavier nucleus. In the image, we see atomic - like entities combining to form a helium nucleus ($^{4}He$) and release energy, which is characteristic of nuclear fusion. Nuclear fission involves the splitting of a large nucleus into two or more smaller nuclei. The release of energy or radioactivity of products is not the key differentiator between fission and fusion in this context.

Answer:

nuclear fusion because atomic nuclei combine to form a heavier nucleus