When modeling processes or analyzing tasks, business rules can be uncovered by asking about:

Business rules are the specific, testable directives that guide business behavior, make decisions, or constrain processes. When modeling a process, the flow shows what happens and in what order. To uncover the underlying business rules, the analyst must ask why things happen a certain way. Asking about the reasons for choosing a particular course of action or making a specific decision forces stakeholders to articulate the logic, policies, and constraints that govern the process, which are the business rules.

A. Overlapping tasks identify process inefficiencies or concurrency, not the rules that govern the individual tasks themselves.
B. Work performed out of sequence identifies exceptions or alternate paths, but not the fundamental rules dictating the standard process.
D. Task transitions that hinder performance identify process bottlenecks or weaknesses, not the business logic or policies.

Project Management Institute. (2017). The PMI Guide to Business Analysis. Section 6.4.2, Business Rules Analysis, p. 216.

Project Management Institute. (2015). Business Analysis for Practitioners: A Practice Guide. Section 5.4.2, Specify and Model Requirements, p. 85.