A.A(P/F,i,1) +A(P/F,i,2)+A(P/F,i,4)+A( P/A,i,n-1)+A(P/F,i,n)
B.A(P/F,i,1) +A(P/F,i,2)+A(P/F,i,4)+A( P/A ,i,n -1)(P/F,,i,4)+A(P/F,i,n)
C.A(P/F,i,1) +A(P/F,i,2)+A(P/F,i,4)+A(P/A,i,n-5)(P/F,i,4)+A(P/F,,i,n)
D.A(P/F,i,1) +A(P/F,i,2)+A(P/F,i,4)+A( P/A,i,n-5)(P/F,i,5)+A(P/F,i,n)
正确答案:C