A 6 years old female child presents with severe pain in throat and odynophagia, since one week General examination revealed, cervical lymphadenopathy, but no signs or symptoms of upper airway obstruction. Intra-oral examination revealed swelling, redness and protrusion of both tonsils, Most common causathe agent is:
Haemolytic streptococcus Non-haemolytic streptococcus H. influenza Staphylococci