This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: Parasitology, Subject name: Microbiology
Protozoa associated with Megaesophagus, Megacolon, Romanas sign, chagoma: 
Select and explain. 
A. Trypanosome, B. Amoeba, C. Giardia, D. Gnathostoma
A: Trypanosome
Answer: A: Trypanosome 
Explanation: Ans. is 'a' i.e., Trypanosoma(Ref: Chatterjee, 12th/e, p. 52)* Megaesophagus and Megacolon occur as complications of Chronic Chagas disease.* T. cruzi causes Chagas disease (Romana sign, chagoma) also seen.* ECG changes like sinus tachycardia, increased PR interval, T wave changes and low QRS voltage, Myocarditis occurs.