John wants to send Marie an email that includes sensitive information, and he does not trust the network that he is connected to$.$ Marie gives himthe idea of using PGP$.$ What should John do to communicate correctly using this type of encryption?A$.$ Use his own private key to encrypt the message.B$.$ Use his own public key to encrypt the message.C$.$ Use Marie$$s private key to encrypt the message.D$.$ Use Marie$$s public key to encrypt the message.