单项选择题

A.①→④→②→③→⑤→⑧→⑥→⑦
B.①→④→②→③→⑤→⑥→⑧→⑦
C.④→①→②→③→⑤→⑧→⑥→⑦
D.④→①→②→③→⑤→⑥→⑧→⑦