A farmer presents with pustules, which show Gram Positive Cocci on smear. Culture shows Beta hemolysis, and organisms are Catalase negative. To show that the identified organism is group A streptococci, which of the following test should be done?
A. Bacitracin sensitivity
B. Optochin sensitivity
C. Novobiocin sensitivity
D. Bile solubility
Correct answer : A. Bacitracin sensitivity