Question: A 4 year old boy comes into the clinic with a history of severe infections. Analysis of his blood reveals that he has only IgM antibodies and no other isotypes. His T cells circulating in blood look perfectly normal. Which of the following gene mutation(s) could explain these observations? Group of answer choices CD40L and AID RAG1/2 and DNA-PK ID2 and Artemis RAG1/2 and TdT