Answer:
Iron is the element that is produced at the limit of the reaction.
Step-by-step explanation:
In nuclear fusion 2 lighter nuclei are combined together into a single nucleus releasing a tremendous amount of energy in the process.
Up to fusion of iron the reaction of fusion is exothermic but when iron atom pops out the reaction becomes endothermic and it requires very high amount of energy to fuse iron atoms which is not available thus marking an end to the fusion reaction.