Review Question - QID 210636

A 4-year-old boy presents to the pediatrician's office for a well-child checkup. He does not speak during the visit and will not make eye contact. The father explains that the child has always been shy with strangers. However, the child speaks a lot at home and with friends. He can speak in 4 word sentences, tells stories, and his parents understand 100% of what he says. He names colors and is starting to recognize letters. However, his pre-kindergarten teachers are concerned that even after 5 months in their class, he does not speak during school at all. The father notes that he is equally as shy in church, which he has been going to his entire life. His temperature is 98.7°F (37°C), blood pressure is 105/58 mmHg, pulse is 90/min, respirations are 18/min, and oxygen saturation is 99% on room air. Which of the following is the most likely diagnosis?