<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 3-year-old boy is brought to the physician by his mother for the evaluation of delay in attaining developmental milestones. He could sit upright by 14 months and has not been able to walk without support. He can build a tower of 3 blocks and cannot use utensils to feed himself. He speaks in unclear 2-word phrases and cannot draw a circle yet. His mother has noticed him hitting his head against the wall on multiple occasions. He is at 20th percentile for height and at 50th percentile for weight. Vitals signs are within normal limits. Examination shows multiple lacerations of his lips and tongue. There are multiple healing wounds over his fingers. Neurological examination shows increased muscle tone in all extremities. Laboratory studies show:Hemoglobin 10.1 gdLMean corpuscular volume 103 μm3SerumNa 142 mEqLCl- 101 mEq:K 4.1 mEqLCreatinine 1.6 mgdLUric acid 12.3 mgdLWhich of the following is the most likely cause of this patients findings?? A: FMR1 gene mutation, B: MECP2 gene mutation, C: Branched-chain alpha-ketoacid dehydrogenase complex deficiency, D: Hypoxanthine-guanine phosphoribosyltransferase deficiency, E: Microdeletion of paternal chromosome 15,  <response>: Based on the information provided in the question stem, the key findings in this 3-year-old boy are:- Delayed developmental milestones - could sit at 14 months, cannot walk without support, limited speech, unable to use utensils or draw- Head banging behavior- Increased muscle tone - Lab results showing anemia, increased MCV, hyperuricemia, and renal insufficiencyThis constellation of developmental delay, self-injurious behavior, hypertonia, and lab abnormalities points towards a genetic disorder. The elevated MCV and hyperuricemia make me think of Lesch-Nyhan syndrome, caused by a deficiency in the purine recycling enzyme hypoxanthine-guanine phosphoribosyltransferase HGPRT. This leads to excess uric acid production and its complications. The other answer choices do not fit with the clinical and lab findings described.D: Hypoxanthine-guanine phosphoribosyltransferase deficiency 