A 42-year-old man with a history of penicillin allergy presents to the clinic with a 7-day history of fever, joint pain (knees and ankles), and a pruritic maculopapular rash on his trunk and limbs. He was started on amoxicillin 5 days ago for a respiratory tract infection. On examination, he has lymphadenopathy and hepatosplenomegaly. Serum complement levels (C3, C4) are low. Which type of hypersensitivity reaction best explains his clinical presentation?