Choose the correct statements about Nissl's granules from the codes given below:
$I.$ There are regular masses of ribosomes
$II.$ There are irregular masses of ribosomes and $ER$
$III.$ There are granular bodies
$IV.$ They synthesise proteins in the cell

• A
  Only $I$
• B
  $I$ and $III$
• C
  $I$ and $IV$
• D
  $II, III$ and $IV$