What is called the type of access control where there are pairs of elements that have the least upper bound of values and greatest lower bound of values? 

Answer options:

A. Mandatory model
B. Discretionary model
C. Lattice model
D. Rule model

C

In a lattice model, there are pairs of elements that have the least upper bound of values and greatest lower bound of values. Reference(s) used for this question: KRUTZ, Ronald L. & VINES, Russel
D., The CISSP Prep Guide: Mastering the Ten Domains of Computer Security, 2001, John Wiley & Sons, Page 34.