please explain the answer to me

Dear student, In the cross , the maximum percentage of recombinants that can be obtained is 50%. Whereas , the maximum percentage of parental types that can be obtained is 100%. This is because only one sister chromatid of homologous chromosomes cross over with each other. This crossing over results in recombination. Since only one sister chromatid of homologous chromosomes cross over each other, the maximum recombinants that can be obtained are 50%, since the other two chromatids do not cross over and are inherited as such (parental type). Moreover, the smaller the distance between two genes, greater is the chance of their linkage , such linked genes are inherited together without recombination, or in other words, remain as parental type. Thus, the maximum percentage of parental types can be 100%. Hence correct answer is option 1. Regards