Cytochrome C Is Normally Attached to the Outer Surface of the Inner

Cytochrome c is normally attached to the outer surface of the inner mitochondrial membrane, where it participates in electron transport.However, when released into the cytoplasm, it can influence the fate of the cell by:

A) Activating mitogen-activated protein kinases, thereby pushing the cell through the G1 checkpoint.
B) Binding to death receptors, thereby triggering apoptosis.
C) Entering the nucleus, where it activates transcription by removing the retinoblastoma protein pRb from the transcription factor E2F.
D) Binding tightly to the Ras protein, thereby causing exit from the cell cycle.
E) Helping in the assembly of the apoptosome, which triggers apoptosis.