thE phrAsE "olDEr AnD DEEpEr FunCtions" in thE First sEntEnCE rEFErs to ______.
A．thE grAmmAtiCAl struCturE oF lAnguAgE
B．thE ExprEssion oF Emotions through sounD
C．thE trAnsmission oF inFormAtion through writtEn lAnguAgE
D．thE purEly inFormAtivE pArt oF lAnguAgE