The plant hormone used to destroy weeds in a field is:

What is the direction of transport of auxin?

$I.$ Cell elongation
$II.$ Cell division
$III.$ Cell differentiation
Among the above mentioned,what is/are the function$(s)$ of auxin?

Auxins are

Which member of the auxin group is widely used to kill dicotyledonous weeds?

$A$: If a plant is kept horizontally,auxin accumulates on the lower surface.
$R$: Displacement of statoliths and other cell organelles to the lower surface modifies the translocation pattern of auxin.