To solve this problem, we need to understand the significance of Dr. F. Went's experiment with coleoptile tips and agar.$\newline$Let's break down the experiment and its implications:$\newline \bullet$Dr. F. Went removed coleoptile tips and placed them on agar for one hour.$\newline \bullet$The agar, after being in contact with the coleoptile tips, was then placed on one side of freshly-cut coleoptile stumps.$\newline \bullet$This setup caused the coleoptile stumps to bend, indicating the presence of a growth-promoting substance.$\newline$The significance of this experiment is as follows:$\newline \bullet$The bending of the coleoptile stumps demonstrated that the substance responsible for growth was diffusible and could be transferred to the agar.$\newline \bullet$This experiment was crucial in the isolation and identification of auxin, a plant hormone responsible for growth.$\newline$Therefore, the experiment made possible the isolation and exact identification of auxin.$\newline$This corresponds to Option 1.