Which of these medications is most likely responsible for this patient's hypoglycemic reactions?

A 56-year-old man with a history of type 2 diabetes presents to his physician for a follow up. He complains of recurrent hypoglycemic reactions to his medications.

Which of these medications is most likely responsible for this patient’s hypoglycemic reactions?
A- Glyburide
B- Glucagon
C- Metformin
D- Acarbose
E- Rosiglitazone