b. As A and B get relatively far apart, multiple crossovers start to occur. The number of crossovers increases linearly with distance, but the number of noticeable crossovers does not continue to increase linearly. This is because some multiple crossovers switch the A’s and B’s back to where they were in the first place. Only those crossovers that switch parental alleles to give new allele combinations can be detected and counted as recombinants.