The method that uses restriction digests to genotype individuals at a SNP locus works if which condition is met?
1) PCR primers bind to different locations depending on the SNP alleles
2) a microarray is available that distinguishes between the two alleles by hybridization
3) the restriction enzyme cuts the DNA from one allele but not the other
4) Sanger sequencing is cheaper than next-generation sequencing
5) we can visualize the restriction enzyme using protein gel electrophoresis