What is the final elemental product created in the core fusion sequence of a massive supergiant before collapse ensues?

Answer

Iron-group elements (Fe, Ni)

In the late stages of a massive supergiant, the innermost core contracts and heats until it is composed of iron-group elements (Fe, Ni), representing the end point of energy-releasing fusion.

What is the final elemental product created in the core fusion sequence of a massive supergiant before collapse ensues?
Elementastronomycompositionstargiant