<prompt> Please answer with one of the option in the bracket. Write reasoning in between . Write answer in between .Q:A 2-day-old boy born to a primigravida with no complications has an ear infection. He is treated with antibiotics and sent home. His parents bring him back 1 month later with an erythematous and swollen umbilical cord still attached to the umbilicus. A complete blood cell count shows the following:Hemoglobin 18.1 gdLHematocrit 43.7Leukocyte count 13,000mm3Neutrophils 85Lymphocytes 10Monocytes 5Platelet count 170,000mm3The immunoglobulin levels are normal. The absence or deficiency of which of the following most likely led to this patients condition?? A: CD18, B: Histamine, C: Prostaglandin E2, D: TNF, E: IL-1,  <response>: This is a medical question asking about the likely deficiency that led to an erythematous and swollen umbilical cord in a newborn boy with a recent ear infection. The lab results show elevated white blood cell count with increased neutrophils, indicating inflammation or infection. The choices list various cytokines and cell adhesion molecules. This appears to be a case of delayed separation of the umbilical cord due to deficiency in neutrophil recruitment and inflammation. Histamine, prostaglandin E2, TNF, and IL-1 are pro-inflammatory mediators that promote inflammation. CD18 is an integrin molecule involved in neutrophil adhesion and migration to sites of inflammation. Lack of CD18 would impair neutrophil recruitment and lead to delayed umbilical cord separation.A: CD18 