Task: Question Answering
Input (English): Question: In the sequencing of DNA by the Sanger method: 
 Options:  <1> The 2`-3` dideoxynucleotides are essential. <2> It is necessary to use suicide inhibitors of DNA polymerase. <3> DNA must maintain its double helix structure. <4> The DNA is hydrolyzed selectively. <5> The restriction endonucleases are fundamental.
Output (English): 1