A 28-year-old male construction worker from Delhi presents with progressive cough, night sweats, and weight loss over 4 months. He lives in a single-room tenement with 6 family members, works in poorly ventilated construction sites, and has a history of malnutrition. His father was treated for tuberculosis 5 years ago. Chest X-ray shows cavitary lesions in the right upper lobe. Sputum smear microscopy is positive for acid-fast bacilli. Which of the following BEST represents the web of causation for tuberculosis in this patient?