Assume now that A starts a run of this protocol with B$.$ However, the connection is intercepted by the adversary C$.$ Show how C can start a new run of the protocol using reflection $$i$.$e$.,$ C sending a message back to A based on what it received from A$,$ causing A to believe that she has agreed on a fresh key with B $$in spite of the fact that she has only been communicating with C$.$ Thus, in particular, the belief in $$a$$ is false.