Which of the following helps in the ascent of sap?

According to one vital force theory,the ascent of sap is due to the active pulsation of the innermost layer of the cortex. This theory was proposed by:

$A$ : Root pressure is dynamic and is always a positive hydrostatic pressure.
$R$ : It is a universal phenomenon and develops under absorption lag.

Water enters which part of the root first?

Water molecules are highly polar. The polar end of a molecule attracts opposite charges on another water molecule (acting like a magnet). How would you explain this property of water with reference to the upward movement of water? Comment on the upward movement of water given the intermolecular hydrogen bonding in water.

Which of the following is more during the night?