Homer wants to send a secure email to Marge so he decides to encrypt it. Homer wants to ensure that Marge can verify that he sent it. Which of the following does Marge need to verify the certificate that Homer used in this process is valid?
A. The CA's private key
B. The CA's public key
C. Marge's public key
D. Marge's private key
Answer: B. The CA's public key