Which of the following hormones is produced during leaf fall?

$ABA$ (Abscisic Acid) possesses:

Which one of the following generally acts as an antagonist to gibberellins?

$ABA$ (Abscisic acid) is involved in:

$I.$ Antagonist to $GA$
$II.$ Promotes bud dormancy
$III.$ Promotes stomatal closure
$IV.$ Promotes abscission layer
Identify the hormone/s which promote/s all these events in plants and choose the correct option.

Which hormone induces senescence in plants?