\documentclass[
$if(fontsize)$
  $fontsize$,
$endif$
$if(papersize)$
  $papersize$paper,
$endif$
$for(classoption)$
  $classoption$$sep$,
$endfor$
$if(journaltype)$
  $journaltype$,
$else$
  journal,
$endif$
]{IEEEtran}