Which theory explains the unidirectional movement of water against gravity in plants/trees?

Maximum transpiration occurs in

Select the incorrect statement from the following.

Stomata open in the night at alkaline or neutral $pH$ (in the atmosphere of ammonia vapours). This statement was given by

What causes the opening and closing of guard cells of stomata during transpiration? Describe point-wise.

Select the correct option regarding the factors affecting transpiration.
$I -$ Temperature
$II -$ Light
$III -$ Structure of stomata
$IV -$ Humidity
$V -$ Number and distribution of stomata
$VI -$ Percentage of open stomata
$VII -$ Water status of the plant
$VIII -$ Wind speed
Identify the external factors and internal factors respectively.