The title that best expresses the ideas of this passage is ______.

A．a linguist
B．an attorney
C．a scientist
D．an essayist

A．the average man often uses in his own vocabulary what was once technical language not meant for him
B．various professions and occupations often interchange their dialects and jargons
C．there is always a clear-cut nontechnical word that may be substituted for the technical word
D．an educated person would be expected to know most technical terms