Among the following which is the correct expression for taylor's theorem in two variables for the function f (x, y) near (a, b) where h=x- a&k=y-b upto second d

Among the following which is the correct expression for Taylor's theorem in two variables for the function f (x, y) near (a, b) where h=x- a&k=y-b upto second degree a)fa +h,b+ k)-f(a.b) +Aa.b)+s(a.b) +a (a. b) + b)+ ab) -. fathb +) =Fa.b)+sla.b)+6la.b) + ab) + s(a.b) + a.b) Cfath,b+k) = f(a. b) + a,b) + a,b)+ a.b)+ a,b) ( fa t h,b +) -f(a.b) + fa,b)+ a.b)+fab) + 2 fay(a,b) + yab).