Presidents Tend to Distrust Career Diplomats Because

Presidents tend to distrust career diplomats because:

A) presidents cannot be certain of a diplomat's political leanings and partisan identification.
B) most recent presidents have lacked trust in bureaucratic expertise in any field.
C) they typically do not know the language and culture that the diplomats are meant to serve.
D) under the modern presidential system, more personal responsibility has been heaped on the presidency in international affairs.