<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 5-year-old boy is brought to the clinic by his mother for an annual check-up. The family recently moved from Nebraska and is hoping to establish care. The patient is home schooled and mom is concerned about her sons development. He is only able to say 2 to 3 word sentences and has been behind on his alphabet. He always seems to be disinterested and just seems to be behind. The patient is observed to be focused on playing with his cars during the interview. Physical examination demonstrate a well-nourished child with poor eye contact, a prominent jaw, a single palmar crease, and bilaterally enlarged testicles. What is the most likely mechanism of this patients findings?? A: CGG trinucleotide repeat expansion, B: CTG trinucleotide repeat expansion, C: Meiotic nondisjunction of chromosome 21, D: Microdeletion of the short arm of chromosome 5, E: Microdeletion of the long arm of chromosome 7,  <response>: This is a clinical vignette describing a 5-year-old boy with delayed speech development, poor eye contact, prominent jaw, single palmar crease, and enlarged testicles. The question asks about the most likely underlying mechanism for these findings.Choice A describes a CGG trinucleotide repeat expansion, which is associated with fragile X syndrome. This is characterized by intellectual disability, developmental delay, autistic features, and macroorchidism in males. The clinical features described are consistent with fragile X syndrome.Choice B describes a CTG repeat expansion, which is associated with myotonic dystrophy type 1. This would not explain the clinical findings in the vignette. Choice C describes meiotic nondisjunction of chromosome 21, leading to trisomy 21 or Down syndrome. While this can cause intellectual disability, the other features in the vignette are not typical of Down syndrome.Choice D describes a microdeletion of chromosome 5p, associated with Cri du Chat syndrome. This can cause developmental delay but does not explain the other clinical features.Choice E describes a chromosome 7q microdeletion, associated with Williams syndrome. This does not fit the clinical scenario described.In summary, the clinical features described, including developmental delay, poor eye contact, prominent jaw, and macroorchidism, are most consistent with fragile X syndrome due to a CGG trinucleotide repeat expansion.A: CGG trinucleotide repeat expansion 