Which of the following theories is primarily proposed to explain the upward movement of water from roots to the shoot?

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.

The continuity of the water column in the $xylem$ is maintained due to

What is the force developed in the cortex of the root that pushes water from the soil into the xylem of the root?

Keeping a freshly cut leafy twig in a $fuchsin$ solution reveals that:

Guttation is caused by which of the following?