I'm not 100% sure, but I think it's "ae". ae means aged in latin! hopefully this helps:)
Science says that dead stars become neutrons when they die. Neutron stars are characterized by having a small radius with a high density. Protons and electrons are compressed in a very tight space making it highly dense. As it gets more compresses, it causes implosion in the form of shockwaves called supernova.
Thus, the answer is C.
Re and fer, re means “to” and fer means “bear” to bear.
