Which of the following is an objective of public key infrastructure (PKI)?

An objective of public key infrastructure (PKI) is to independently authenticate the validity of the sender’s public key. PKI is a system that uses cryptographic keys to secure communications and transactions. PKI involves a trusted third party called a certificate authority (CA) that issues digital certificates that link a public key with an identity. The recipient can use the CA’s public key to verify the sender’s certificate and public key.