how Do you unDErstAnD "spECiAlist", ACCorDing to thE Author
A．A mAn whosE joB is to trAin othEr pEoplE.
B．A mAn who hAs BEEn trAinED in morE thAn onE FiElD.
C．A mAn who CAn sEE thE ForEst rAthEr thAn thE trEEs.
D．A mAn whosE ConCErn is mAinly with tEChniCAl or proFEssionAl mAttErs.