How many of the following auxins are synthetic in nature?
IAA, IBA, NAA, 2, 4-D and 2, 4, 5-T
Naphthalene acetic acid (NAA), 2, 4-Dichlorophenoxyacetic acid (2, 4-D) and
2, 4, 5-Trichlorophenoxyacetic acid (2, 4, 5-T) are synthetic auxins and therefore do not occur naturally in plants.