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: Pharmacology
Deaths from lactic acidosis in diabetes mellitus is associated with therapy with which one of the following- 
Select and explain. 
A. Metformin, B. Tolbutamide, C. Phenformin, D. Glipizide
C: Phenformin
Answer: C: Phenformin 
Explanation: Ans. is 'c' i.e., Phenformin