Transpiration and root pressure cause water to rise in plants by

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.

By which of the following is the active uptake of water affected?

Sap ascends in woody stems because of root pressure and

Explain: Root Pressure.

Continuous upward flow of water stream in tall trees is maintained due to . . . . . . .