<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 4-year-old boy is brought by his parents to his pediatricians office. His mother mentions that the child has been producing an increased number of foul stools recently. His mother says that over the past year, he has had 1 or 2 foul-smelling stools per month. Lately, however, the stools are looser, more frequent, and have a distinct odor. Over the past several years, he has been admitted 4 times with episodes of pneumonia. Genetic studies reveal a mutation on a specific chromosome that has led to a 3 base-pair deletion for the amino acid phenylalanine. Which of the following chromosomes is the defective gene responsible for this boys clinical condition?? A: Chromosome 15, B: Chromosome 4, C: Chromosome 17, D: Chromosome 22, E: Chromosome 7,  <response>: This is a clinical vignette describing a 4-year-old boy with a history of recurrent pneumonia and recent increase in foul-smelling stools. The key details are the foul-smelling stools, history of recurrent pneumonia, and genetic studies showing a 3 base-pair deletion leading to loss of phenylalanine. This clinical presentation is most consistent with cystic fibrosis, an autosomal recessive disorder caused by mutations in the CFTR gene located on chromosome 7. The loss of phenylalanine specifically points to the most common mutation in CFTR, ΔF508. Therefore, the defective gene is located on chromosome 7.E: Chromosome 7 