Absence of trophic factors causes caspase activation. The non-phosphorylation of Bad protein causes ions to enter mitochondria and Cyt C to exit. Cyt C + Apaf1 --> procaspase 9 --> caspase 9 --> procaspase 3 --> caspase 3 --> cleavage of substrates, cell death.

A) Trophic factors prevent caspase activation.
B) Bad protein phosphorylation inhibits apoptosis.
C) Caspase activation is independent of Cyt C release.
D) Cyt C release leads to caspase activation and cell death.