This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Unknown
A patient who was initially smear positive, who began the treatment and who remained or became smear positive again at five months or later during the course of treatment is called as: 
Select and explain. 
A. Defaulter, B. Failure case, C. Relapse, D. None of the above
B: Failure case
Answer: B: Failure case 
Explanation: Failure case: A patient who was initially smear positive, who began
Rx and who remained or became smear positive again at five months or later during the course of Rx.
Relapse: A patient who returns sputum smear positive having previously been treated for tuberculosis and declared cured after the completion of his treatment.
Return after default: A patient who returns sputum smear positive, after having left Rx for at least two months.