Select the correct statements with reference to chordates.
$A$. Presence of a mid-dorsal,solid and double nerve cord.
$B$. Presence of closed circulatory system.
$C$. Presence of paired pharyngeal gill slits.
$D$. Presence of dorsal heart.
$E$. Triploblastic pseudocoelomate animals.
Choose the correct answer from the options given below:

• A
  $C, D$ and $E$ only
• B
  $A, C$ and $D$ only
• C
  $B$ and $C$ only
• D
  $B, D$ and $E$ only