Iron-carbon and TTT diagrams are

Question

Which one of the following statements is correct?                                    

(a) Iron-carbon and TTT diagrams are both equilibrium diagrams.

(b) Iron-carbon and TTT diagrams are both non-equilibrium diagrams.

(c) Iron-carbon diagram is an equilibrium diagram but TTT diagram is a non-equilibrium diagram.             

(d)  Iron-carbon diagram is a non-equilibrium diagram but TTT diagram is an equilibrium diagram