What is a major difference in the write cache feature between a CLARiiON CX3 and a CX4 upon failure of an SP?

A.
Write cache is disabled on the CX3 but not on the CX4.

B.
Write cache is disabled on the CX4 but not on the CX3.

C.
Write cache is dumped to NVRAM on the CX3 but not on the CX4.

D.
Write cache is dumped to the vault on the CX4 but not on the CX3.