Consider the following statements regarding Thevenin’s Theorem:1.Thevenin’s theorem states that any linear bilateral network can be replaced by an equivalent voltage source in series with a resistance.2.Thevenin resistance is calculated by deactivating all independent sources and finding equivalent resistance seen from terminals.3.The open circuit voltage across terminals is equal to Thevenin voltage of the network.4.Thevenin equivalent is valid only for DC circuits and cannot be applied to AC circuits.Which of the above statements is/are correct?