Question

which element would most likely require a supernova to form? a iron b carbon c oxygen d helium

Explanation:

In a star, lighter elements like hydrogen and helium fuse to form heavier elements through nuclear fusion. Elements up to iron can be formed in the core of a massive star during its normal life - cycle. But to form elements heavier than iron, a supernova is required. Carbon, oxygen, and helium are lighter than iron and can be formed through normal stellar nucleosynthesis processes in the star's core. Iron is the last element formed in normal stellar fusion before a supernova event.

Answer:

A. Iron