Which process is shown in the figure below?

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.

Stomata open during day time because the guard cells

Identify $X$ and $Y$ from the figure.

Hydathodes perform the function of

According to the proton transport theory,which ion plays an important role in the opening and closing of stomata?