Final answer:
The Registration authority in PKI performs administrative functions like verifying requester identities before certificate issuance.
Step-by-step explanation:
The component of Public Key Infrastructure (PKI) responsible for the administrative functions, such as verifying the identity of individuals and organizations requesting a digital certificate, is B: Registration authority. The registration authority acts as the verifier of the certificate requester's credentials before the certification authority issues a certificate. It is an integral part of maintaining the security and integrity of the PKI ecosystem by ensuring that digital certificates are granted to legitimate entities.