Explanation

In Mendelian monohybrid crosses with complete dominance, the genotypic ratio is 1:2:1 and phenotypic ratio is 3:1. However, in cases of incomplete dominance or codominance, the phenotypic ratio matches the genotypic ratio (1:2:1). The question asks when they are identical. Incomplete dominance results in a 1:2:1 phenotypic ratio which is identical to the genotypic ratio. Wait, let me re-read carefully. 'In populations genotypic and phenotypic ratios are identical in cases of___________________?' Actually, in incomplete dominance, the phenotype directly reflects the genotype, so the ratios are indeed identical (1:2:1). So C is correct. Let me double check standard biology MCQs on this topic. Often, questions like this refer to 'Incomplete dominance' or 'Codominance'. The current answer is C. I will verify if A could be correct. In complete dominance (Mendel's monohybrid), ratios are different. So C is definitely the intended answer. I will mark isCurrentAnswerCorrect as true.