Given that the system is inStateA1, the sequence of triggers that will move the system toStateCmust take into account the transitions and their associated triggers as defined in the UML state diagram. Starting from StateA1, the triggera5will cause a transition withinStateA, followed bya6, which moves toStateA2. The triggera5is not relevant as it is an internal transition inStateA1. Then,a3(the exit action forStateA) anda2 would be followed to leaveStateAaltogether. Once out ofStateA,a1is used to transition toStateB, wherea10is an entry action, not a trigger. Finally, to get fromStateBtoStateC, the triggersa11followed bya12are needed.
This sequence of triggers reflects the correct usage of exit, entry, and transition triggers as defined by UML state machine semantics.