The relative location of four genes on a chromosome can be mapped from the following data on crossover frequencies Genes B and D Frequency of Crossover 5% Cand A 15% A and B 30% C and B 45% Cand D 50% Which of the following represents the relative positions of these four genes on the chromosome? 1. ABCD 2. ADCB 3. CABD 4. CBAD