Which one of the following hormones is not found in plants?

Step-by-step solution

2,4 – D is the synthetic or exogenous auxin. 2,4-Dichlorophenoxyacetic acid (usually called 2,4-D) is an organic compound with the chemical formula C 8 H 6 Cl 2 O 3 . It is a systemic herbicide which selectively kills most broadleaf weeds by causing uncontrolled growth in them, but it leaves most grasses such as cereals, lawn turf and grassland relatively unaffected.