Review Question - QID 213579

A 12-year-old boy is brought to the emergency department after hiking in the woods with his friends. His friends say that he slipped, fell during the hike, and scraped his arms yesterday. On presentation, he is found to have slow bleeding from the cuts, which are also noted to be inflamed and exuding pus. He says that he often gets infections and that this has occurred since birth. Furthermore, physical exam reveals a thin, extremely pale boy with platinum blond hair and pale eyes. Which of the following processes is most likely disrupted in this patient?