Which among the following chemical is a plant hormone that can be used as a herbicide to defoliate broad-leafed plants ?
[A]Acetic Acid
[B]Indole Acetic Acid
[D]Gibberellic Acid

Indole Acetic Acid
Indole-3-acetic acid (IAA) is the most common, naturally-occurring, plant hormone of the auxin class. Apart from this, the 2,4,5-Trichlorophenoxyacetic acid (2,4,5-T), and 2,4-Dichlorophenoxyacetic acid (2,4-D) are also herbicide used to defoliate broad-leafed plants.