First chemical herbicide ever produced in world is

Answer: Option A

2, 4-Dichlorophenoxyacetic acid has been one of the oldest and most widely available herbicides and defoliants in the world since 1945.
It is an organic compound with the chemical formula C₈H₆Cl₂O₃, which is commonly known as 2, 4-D. It is a systemic herbicide that kills most broadleaf weeds by causing uncontrolled growth in crop plantations.