单项选择题
A.5 B.6 C.1 D.4
A.*+-+ab/c+def+gh、ab+cde+/-f+gh+* B.*+-ab+/c+def+gh、ab+cde+/-f+gh+* C.*+-+ab/c+def+gh、ab+cde+/-+fgh+* D.*+-+ab/c+edf+gh、a+bcde+/-f+gh+*
A.n-i B.n-i+1 C.n-i-1 D.i