4. Lower-level management function most effectively when they have thorough training and unimpeded communication with workers, supervisors, and one another.
(A) management function most effectively when they have
(B) managers function most effectively when they have
(C) management functions most effectively when they have
(D) managers function most effectively when they have received(B)
(E) management functions most effectively when it has
答案B,谁能替我翻译一下什么意思。D是因为have received 1.改变了原句意思,2,received thorough unimpeded communication with workers, supervisors, and one another 逻辑意思不通两个原因吗?