Task: Question Answering
Input (English): Question: The polymerase chain reaction (PCR) encompasses three processes. Select sequence order: 
 Options:  <1> Extension → Fusion → Denaturation. <2> Fusion → Denaturing → Extension. <3> Denaturing → Fusion → Extension. <4> Denaturing → Extension → Fusion. <5> Extension → Denaturation → Fusion.
Output (English): 3