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 farmer presents with pustules,which show Gram Positive Cocci on smea

1.	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
Answer» B. Optochin sensitivity