The correct answer is option (1) as the correct sequence of steps involved in the process of PCR are : (C) Denaturation (A) Annealing (D) Treatment with Taq polymerase and deoxynucleotides (E) Extension (B) Amplification ( ∼1 billion times). That is C⟶A⟶D⟶E⟶B Option (2), (3) and (4) are incorrect as they represent incorrect sequence.