下列哪种说法不正确（）

A.心可分为一尖、一底、两面、三缘，表面有4条沟

B.心尖位置大致在左侧第5肋间隙锁骨中线稍内一点

C.心的前面位于胸骨和肋骨的后面，故此面亦称胸肋面

D.前、后室间沟在心尖左侧的汇合处稍凹陷，称心尖切迹

E.后房间沟、后室间沟与冠状沟的相交处称房室交点

________ the explanation of the book, we finally understood the meaning of the passage. [      ]

A. With the help of  

B. Under the help of

C. After the help of  

D. By the help of