With the BLP model, security policies prevent information flowing downwards from a:

A.
Low security level

B.
High security level

C.
Medium security level

D.
Neutral security level

Explanation:
Bell-LaPadula is a state machine model capturing confidentiality aspects of access
control. Access permissions are defined through an Access Control matrix and through a
partial ordering of security levels. Security policies prevent information flowing
downwards from a high security level to a low security level. BLP only considers the
information flow that occurs when a subject observes or alters an object.