Go through the following statements regarding starch digestion. Separate true and false statements and select the correct option accordingly.
$I.$ Digestion of starch starts from the mouth.
$II.$ Around $30 \%$ of the starch is digested in the stomach.
$III.$ Digestion of food requires the action of pancreatic juices.
$IV.$ Digestion of food is completed in the longest part of the alimentary canal.

• A
  All are true.
• B
  $II$ is false while $I, III$ and $IV$ are true.
• C
  $II$ and $III$ are false while $IV$ and $I$ are true.
• D
  $II$ and $IV$ are false while $III$ and $I$ are true.