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

Answer options:

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.

D