Which of the following statements about designing an enterprise application is TRUE?

A.
Due to the realities of a commercial system, performance requirements should be resolved in
the analysis phase of the project.

B.
A three or more tier architecture should be considered in order to facilitate scalability.

C.
In modelling a system that will have many concurrent users, collaboration diagrams are more
useful than sequence diagrams.

D.
By definition, each use case represents a set of actions that are performed atomically; it
therefore maps directly to a transaction.