Match the symmetric key distribution mechanism on the left with the appropriate description on the right. Each distribution mechanism may be used once, more than once, or not at all. The sender's key is sent to a recipient using a DiffieHellman key exchange. The sender's key is copied to a USB drive and handed to the recipient. The sender's key is sent to the recipient using publickey cryptography. The sender's key is burned to a CD and handed to the recipient.