Identification of surplus teacher

I am an assistant teacher in govt aided High school in west bengal. I was appointed in 12/09/2009 in English language group in Pass category and S.C quota.My post is normal and permanent post. Due to students roll strenght degradation in our school the govt has issued notice to our school to identify surplus teacher in English language group and has instucted to keep only two teachers in english langusge group.Presently there are 3 teachers in English language group. Mr.A was appointed in 1990 in English language group as Post Graduate teacher and post graduate scale of pay in general quota and his post his normal post. Mr.B was appointed in 1995 in an additional post in English language group as POST GRADUATE" teacher and in POST GRADUATE scale of in "GENERAL" quota.Later on 1997 his "ADDITIONAL" post was declared " SUBSTANTIVE" post after 2 yrs completion of service. I was appointed in 2009 through school service commission exam in ENGLISH LANGUAGE GROUP in "PASS CATEGORY" and Pass scale of pay in "S.C"quota( reserved category). My post is a normal and permanent post. Now on such circumstances who will be identified as a surplus teacher? According to N.C.T.E act and norms from class 5 to 8 a pass graduare teacher is to be recruited and for class 9 to 10 hons/ P.G category teacher is to recruited. On such circumstances kindly guide me who will be the Surplus teacher amongst 3 of us? And kindly clear me that in case of identifying surplus teacher besides seniority is category, qualification also taken under consideration?Thnx...