：​递归计算是重要的执行手段。例如一种形式的阿克曼函数如下所示：​​​​任何一个A(m, n)都可以递归地进行计算，例如A(1,2)的递归计算过程如下所示：​​A(1,2) = A(0,A(1,1)) = A(0, A(0,A(1,0))) = A(0, A(0,A(0,1)))=A(0,A(0,2))=A(0,3)=4。​​请你按上述方法递归计算下列项，并判断，计算结果正确的是_____。​A: A(1, 8) = 9B: A(2, 0) = 2C: A(2, 1) = 4D: A(1, n) = n+2答案: A(1, n) = n+221、