I think A is best even though there is an assumption that because damaged brain neurons
are prone to become cancerous, it is necessarily the case for other organs.
B) is not right because even though cancerous cells are discovered, the apoptosis process is still not warranted because the argument says that it happens "under certain conditions". Therefore, saying that apoptosis process happens whenever
we discover cancerous cells is not appropriate. Furthermore, "even when cells are not severely damaged" casts some doubts on the validity of the claim.
C) a stroke could cause cell death through other means than the apoptosis process. That we do not know.