Bill is building a project network that involves testing a prototype. he must design the prototype (activity 1), build the prototype (activity 2), and test the prototype (activity 3). activity 1 is the predecessor for activity 2 and activity 2 is the predecessor for activity 3. if the prototype fails testing, bill must redesign the prototype; therefore, activity 3 is a predecessor for activity 1. this is an example of

a. conditional statements.
b. looping.
c. having more than one start node.
d. good network development.
e natural network flow.