Nathalie is exclusively making use of a public key crypto system to communicate with her peers. She would like to send information to Bob while protecting the confidentiality of the content being…

Nathalie is exclusively making use of a public key crypto system to communicate with her peers. She would like to send information to Bob while protecting the confidentiality of the content being sent over the public network. She will ask Bob to send one of his keys that she will use to encrypt the message content before sending it. Which key will Bob send to Nathalie?