Which of the following is true regarding Public Key Infrastructure (PKI)?
A. PKI is intended for e-business use and is typically available through commercial certificate authorities.
B. PKI includes a "tree of trust" that's checked each time a certificate is presented as proof of one's identity.
C. PKI assumes asymmetric encryption to create legally-binding electronic documents.
D. PKI refers to the system and processes used to issue and manage asymmetric keys and digital certificates.