A young boy presents with fever and cough. His father was diagnosed with TB a week ago. The parents don’t want him to have a BAL under anesthesia. Which other samples can be taken for diagnosis?

The key is D. Gastric washing. [A young boy is able to cough up sputum unless it is dry cough where suspected TB is diagnosed by broncho-alveolar-lavage (BAL). As in dry cough TB bacteria contaminate saliva and goes to stomach with swallowed contaminated saliva Gastric-washing can bring out bacteria and detected thereby. So gastric-washing is an alternative to BAL in dry cough].