Which of the following are objections to the root pressure theory of ascent of sap in plants?
$I$. It is not applicable to plants taller than $20 \ m$.
$II$. Ascent of sap occurs even in the absence of a root system.
$III$. Root pressure is almost zero in tall gymnosperms.
$IV$. Root pressure is the only mechanism explaining the ascent of sap.
$V$. Root pressure is not developed in actively transpiring plants.

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