Which of the following offers the highest level of redundancy in the design of a storage system?

Which of the following offers the highest level of redundancy in the design of a storage system?

A.
A Dual Port HBA with a pair of Point-To-Point connections to the SAN.

B.
Two Single Port HBAs connected to a fiber switch.

C.
A Dual Port HBA with a Point-To-Point connection to a SAN.

D.
Two Dual Port HBAs connected to a pair of fiber switches.