A large corporation has data centers geographically distributed across multiple continents. The company needs to securely transfer large amounts of data between the data center. The data transfer can be accomplished physically or electronically, but must prevent eavesdropping while the data is on transit. Which of the following represents the BEST cryptographic solution?
A. Driving a van full of Micro SD cards from data center to data center to transfer data
B. Exchanging VPN keys between each data center via an SSL connection and transferring the data in the VPN
C. Using a courier to deliver symmetric VPN keys to each data center and transferring data in the VPN
D. Using PKI to encrypt each file and transferring them via an Internet based FTP or cloud server