Which is not true of PGP?

A.
It uses a hierarchical trust model.

B.
It uses a web of trust between users.

C.
Public keys are kept in key ring files.

D.
Users can determine how much they trust one another.

Explanation:
Pretty Good Privacy (PGP) is a freeware e-mail security program
developed by Phil Zimmerman in 1991. It does not use a hierarchical trust model, as
in PKI, but a web of trust. This means individual users determine to what degree
they trust each other.